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Author |
Kandemir, Z.; D'Amico, P.; Sesti, G.; Cardoso, C.; Milošević, M.V.; Sevik, C. |
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Title |
Optical properties of metallic MXene multilayers through advanced first-principles calculations |
Type |
A1 Journal article |
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Year |
2024 |
Publication |
Physical review materials |
Abbreviated Journal |
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Volume |
8 |
Issue |
7 |
Pages |
075201-75210 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Having a strong electromagnetic absorption, MXene multilayers are readily envisaged for applications in electromagnetic shields and related prospective technology. However, an ab initio characterization of the optical properties of MXenes is still lacking, due in part to major difficulties with the treatment of metallicity in the first-principles approaches. Here we addressed the latter challenge, after a careful treatment of intraband transitions, to present a thorough analysis of the electronic and optical properties of a selected set of metallic MXene layers based on density functional theory (DFT) and many-body perturbation theory calculations. Our results reveal that the GW corrections are particularly important in regions of the band structure where d and p states hybridize. For some systems, we show that GW corrections open a gap between occupied states, resulting in a band structure that closely resembles that of an intrinsic transparent conductor, thereby opening an additional line of prospective applications for the MXenes family. Nevertheless, GW and Bethe-Salpeter corrections have a minimal influence on the absorption spectra, in contrast to what is typically observed in semiconductor layers. Our present results suggest that calculations within the independent particle approximation (IPA) calculations are sufficiently accurate for assessing the optical characteristics of bulk-layered MXene materials. Finally, our calculated dielectric properties and absorption spectra, in agreement with existing experimental data, confirm the potential of MXenes as effective infrared emitters. |
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Wos |
https://www.webofscience.com/api/gateway?GWVersion=2&SrcApp=brocade2&SrcAuth=WosAPI&KeyUT=WOS:001275 |
Publication Date |
2024-07-22 |
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Series Issue |
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Edition |
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ISSN |
2475-9953 |
ISBN |
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Additional Links |
UA library record; WoS full record |
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Impact Factor |
3.4 |
Times cited |
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Open Access |
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Notes |
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Approved |
Most recent IF: 3.4; 2024 IF: NA |
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Call Number |
UA @ admin @ c:irua:207597 |
Serial |
9309 |
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Permanent link to this record |
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Author |
Çakir, D.; Peeters, F.M.; Sevik, C. |
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Title |
Mechanical and thermal properties of h-MX2 (M = Cr, Mo, W; X = O, S, Se, Te) monolayers : a comparative study |
Type |
A1 Journal article |
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Year |
2014 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
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Volume |
104 |
Issue |
20 |
Pages |
203110 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Using density functional theory, we obtain the mechanical and thermal properties of MX2 monolayers (where M = Cr, Mo, W and X = O, S, Se, Te). The C-centered phonon frequencies (i.e., A(1), A(2)'', E ', and E ''), relative frequency values of A(1), and E ' modes, and mechanical properties (i.e., elastic constants, Young modulus, and Poisson's ratio) display a strong dependence on the type of metal and chalcogenide atoms. In each chalcogenide (metal) group, transition-metal dichalcogenides (TMDCs) with W (O) atom are found to be much stiffer. Consistent with their stability, the thermal expansion of lattice constants for TMDCs with O (Te) is much slower (faster). Furthermore, in a heterostructure of these materials, the difference of the thermal expansion of lattice constants between the individual components becomes quite tiny over the whole temperature range. The calculated mechanical and thermal properties show that TMDCs are promising materials for heterostructures. (C) 2014 AIP Publishing LLC. |
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Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
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Wos |
000337140800063 |
Publication Date |
2014-05-24 |
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ISSN |
0003-6951;1077-3118; |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.411 |
Times cited |
130 |
Open Access |
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Notes |
; Cem Sevik acknowledges the support from Scientific and Technological Research Council of Turkey (TUBITAK-113F096) and Anadolu University (BAP-1306F261 and -1306F281) to this project. We would also like to thank the ULAKBIM High Performance and Grid Computing Center for a generous time allocation for our projects. D. C. was supported by a FWO Pegasus-short Marie Curie Fellowship. Part of this work was supported by the Methusalem foundation of the Flemish Government. ; |
Approved |
Most recent IF: 3.411; 2014 IF: 3.302 |
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Call Number |
UA @ lucian @ c:irua:118379 |
Serial |
1974 |
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Permanent link to this record |
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Author |
Aierken, Y.; Sevik, C.; Gulseren, O.; Peeters, F.M.; Çakir, D. |
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Title |
In pursuit of barrierless transition metal dichalcogenides lateral heterojunctions |
Type |
A1 Journal article |
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Year |
2018 |
Publication |
Nanotechnology |
Abbreviated Journal |
Nanotechnology |
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Volume |
29 |
Issue |
29 |
Pages |
295202 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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Abstract |
There is an increasing need to understand interfaces between two-dimensional materials to realize an energy efficient boundary with low contact resistance and small heat dissipation. In this respect, we investigated the impact of charge and substitutional atom doping on the electronic transport properties of the hybrid metallic-semiconducting lateral junctions, formed between metallic (1T and 1T(d)) and semiconducting (1H) phases of MoS2 by means of first-principles and non-equilibrium Green function formalism based calculations. Our results clearly revealed the strong influence of the type of interface and crystallographic orientation of the metallic phase on the transport properties of these systems. The Schottky barrier height, which is the dominant mechanism for contact resistance, was found to be as large as 0.63 eV and 1.19 eV for holes and electrons, respectively. We found that armchair interfaces are more conductive as compared to zigzag termination due to the presence of the metallic Mo zigzag chains that are directed along the transport direction. In order to manipulate these barrier heights we investigated the influence of electron doping of the metallic part (i.e. 1T(d) -MoS2). We observed that the Fermi level of the hybrid system moves towards the conduction band of semiconducting 1H-MoS2 due to filling of 4d-orbital of metallic MoS2, and thus the Schottky barrier for electrons decreases considerably. Besides electron doping, we also investigated the effect of substitutional doping of metallic MoS2 by replacing Mo atoms with either Re or Ta. Due to its valency, Re (Ta) behaves as a donor (acceptor) and reduces the Schottky barrier for electrons (holes). Since Re and Ta based transition metal dichalcogenides crystallize in either the 1T(d) or 1T phase, substitutional doping with these atom favors the stabilization of the 1T(d) phase of MoS2. Co-doping of hybrid structure results in an electronic structure, which facilities easy dissociation of excitons created in the 1H part. |
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Place of Publication |
Bristol |
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Wos |
000432823800002 |
Publication Date |
2018-05-01 |
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Edition |
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ISSN |
0957-4484 |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.44 |
Times cited |
4 |
Open Access |
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Notes |
; This work was supported by the bilateral project between the The Scientific and Technological Research Council of Turkey (TUBITAK) and FWO-Flanders, Flemish Science Foundation (FWO-VI) and the Methusalem foundation of the Flemish government. Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TRGrid e-Infrastructure), and HPC infrastructure of the University of Antwerp (CalcUA) a division of the Flemish Supercomputer Center (VSC), which is funded by the Hercules foundation. We acknowledge the support from TUBITAK (Grant No. 115F024). ; |
Approved |
Most recent IF: 3.44 |
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Call Number |
UA @ lucian @ c:irua:151451UA @ admin @ c:irua:151451 |
Serial |
5029 |
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Permanent link to this record |
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Author |
Siriwardane, E.M.D.; Demiroglu, I.; Sevik, C.; Peeters, F.M.; Çakir, D. |
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Title |
Assessment of sulfur-functionalized MXenes for li-ion battery applications |
Type |
A1 Journal article |
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Year |
2020 |
Publication |
Journal Of Physical Chemistry C |
Abbreviated Journal |
J Phys Chem C |
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Volume |
124 |
Issue |
39 |
Pages |
21293-21304 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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Abstract |
The surface termination of MXenes greatly determines the electrochemical properties and ion kinetics on their surfaces. So far, hydroxyl-, oxygen-, and fluorine-terminated MXenes have been widely studied for energy storage applications. Recently, sulfur-functionalized MXene structures, which possess low diffusion barriers, have been proposed as candidate materials to enhance battery performance. We performed first-principles calculations on the structural, stability, electrochemical, and ion dynamic properties of Li-adsorbed sulfur-functionalized groups 3B, 4B, 5B, and 6B transition-metal (M)-based MXenes (i.e., M2CS2 with M = Sc, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, and W). We performed phonon calculations, which indicated that all of the above M2CS2 MXenes, except for Sc, are dynamically stable at T = 0 K. The ground-state structure of each M2CS2 monolayer depends on the type of M atom. For instance, while sulfur prefers to sit at the FCC site on Ti2CS2, it occupies the HCP site of Cr-based MXene. We determined the Li adsorption configurations at different concentrations using the cluster expansion method. The highest maximum open-circuit voltages were computed for the group 4B element (i.e., Ti, Zr, and Hf)-based M2CS2, which are larger than 2.1 V, while their average voltages are approximately 1 V. The maximum voltage for the group 6B element (i.e., Cr, Mo, W)-based M2CS2 is less than 1 V, and the average voltage is less than 0.71 V. We found that S functionalization is helpful for capacity improvements over the O-terminated MXenes. In this respect, the computed storage gravimetric capacity may reach up to 417.4 mAh/g for Ti2CS2 and 404.5 mAh/g for V2CS2. Ta-, Cr-, Mo-, and W-based M2CS2 MXenes show very low capacities, which are less than 100 mAh/g. The Li surface diffusion energy barriers for all of the considered MXenes are less than 0.22 eV, which is favorable for high charging and discharging rates. Finally, ab initio molecular dynamic simulations performed at 400 K and bond-length analysis with respect to Li concentration verify that selected promising systems are robust against thermally induced perturbations that may induce structural transformations or distortions and undesirable Li release. |
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Wos |
000577151900008 |
Publication Date |
2020-09-01 |
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ISSN |
1932-7447; 1932-7455 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.7 |
Times cited |
24 |
Open Access |
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Notes |
; Computational resources were provided by the HPC infrastructure of the University of Antwerp (CalcUA), a division of the Flemish Supercomputer Center (VSC), which is funded by the Hercules Foundation. This work was supported, in part, by The Scientific and Technological Research Council of Turkey (TUBITAK) under contract no. 118F512 and the Air Force Office of Scientific Research under award no. FA9550-19-1-7048. This work was performed in part at the Center for Nanoscale Materials, a U.S. Department of Energy Office of Science User. Use of the Center for Nanoscale Materials, an Office of Science user facility, was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under contract no. DE-AC02-06CH11357. This work was supported, in part, by The Scientific and Technological Research Council of Turkey (TUBITAK) under contract no. 118C026. ; |
Approved |
Most recent IF: 3.7; 2020 IF: 4.536 |
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Call Number |
UA @ admin @ c:irua:172693 |
Serial |
6452 |
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Permanent link to this record |
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Author |
Gurel, T.; Altunay, Y.A.; Bulut, P.; Yildirim, S.; Sevik, C. |
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Title |
Comprehensive investigation of the extremely low lattice thermal conductivity and thermoelectric properties of BaIn₂Te₄ |
Type |
A1 Journal article |
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Year |
2022 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
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Volume |
106 |
Issue |
19 |
Pages |
195204-195210 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Recently, an extremely low lattice thermal conductivity value has been reported for the alkali-based telluride material BaIn2Te4. The value is comparable with low-thermal conductivity metal chalcogenides, and the glass limit is highly intriguing. Therefore, to shed light on this issue, we performed first-principles phonon thermal transport calculations. We predicted highly anisotropic lattice thermal conductivity along different directions via the solution of the linearized phonon Boltzmann transport equation. More importantly, we determined several different factors as the main sources of the predicted ultralow lattice thermal conductivity of this crystal, such as the strong interactions between low-frequency optical phonons and acoustic phonons, small phonon group velocities, and lattice anharmonicity indicated by large negative mode Gruneisen parameters. Along with thermal transport calculations, we also investigated the electronic transport properties by accurately calculating the scattering mechanisms, namely the acoustic deformation potential, ionized impurity, and polar optical scatterings. The inclusion of spin-orbit coupling (SOC) for electronic structure is found to strongly affect the p-type Seebeck coefficients. Finally, we calculated the thermoelectric properties accurately, and the optimal ZT value of p-type doping, which originated from high Seebeck coefficients, was predicted to exceed unity after 700 K and have a direction averaged value of 1.63 (1.76 in the y-direction) at 1000 K around 2 x 1020 cm-3 hole concentration. For n-type doping, a ZT around 3.2 x 1019 cm-3 concentration was predicted to be a direction-averaged value of 1.40 (1.76 in the z-direction) at 1000 K, mostly originating from its high electron mobility. With the experimental evidence of high thermal stability, we showed that the BaIn2Te4 compound has the potential to be a promising mid- to high-temperature thermoelectric material for both p-type and n-type systems with appropriate doping. |
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Wos |
000918954800001 |
Publication Date |
2022-11-21 |
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Abbreviated Series Title |
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Edition |
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ISSN |
2469-9969; 2469-9950 |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.7 |
Times cited |
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Open Access |
OpenAccess |
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Notes |
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Approved |
Most recent IF: 3.7 |
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Call Number |
UA @ admin @ c:irua:194384 |
Serial |
7290 |
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Permanent link to this record |
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Author |
Zuniga-Puelles, E.; Levytskyi, V.; Özden, A.; Guerel, T.; Bulut, N.; Himcinschi, C.; Sevik, C.; Kortus, J.; Gumeniuk, R. |
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Title |
Thermoelectric properties and scattering mechanisms in natural PbS |
Type |
A1 Journal article |
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Year |
2023 |
Publication |
Physical review B |
Abbreviated Journal |
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Volume |
107 |
Issue |
19 |
Pages |
195203-195215 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
X-ray diffraction and energy dispersive x-ray spectroscopic analyses showed a natural galena (PbS) crystal from Freiberg in Saxony (Germany) to be a single phase specimen [rock salt (NaCl) structure type, space group Fm3m, a = 5.932(1) angstrom] with stoichiometric composition and an enhanced dislocation density (8 approximate to 1011 cm-2). The latter parameter leads to an increase of the electrical resistivity in the high-temperature regime, as well as to the appearance of phonon resonance with a characteristic frequency coPR = 3.8(1) THz. Being in the same range (i.e., 3-5.5 THz) with the sulfur optical modes of highest group velocities, it results in a drastic reduction (by similar to 75%) of thermal conductivity (K) at lower temperatures (i.e., < 100 K), as well as in the appearance of a characteristic minimum in K at T approximate to 30 K. Furthermore, the studied galena is characterized by phonon-drag behavior and by temperature dependent switch of the charge carrier scattering mechanism regime (i.e., scattering on dislocations for T < 100 K, on acoustic phonons for 100 K < T < 170 K and on both acoustic and optical phonons for 170 K < T < 300 K). The combined theoretical calculation and optical spectroscopic study confirm this mineral to be a direct gap degenerate semiconductor. The possible origins of the second-order Raman spectrum are discussed. |
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Place of Publication |
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Wos |
001009980400008 |
Publication Date |
2023-05-30 |
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Abbreviated Series Title |
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Edition |
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ISSN |
2469-9969; 2469-9950 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.7 |
Times cited |
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Open Access |
Not_Open_Access |
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Notes |
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Approved |
Most recent IF: 3.7; 2023 IF: 3.836 |
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Call Number |
UA @ admin @ c:irua:197808 |
Serial |
8943 |
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Permanent link to this record |
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Author |
Thomen, D.M.N.; Sevik, C.; Milošević, M.V.; Teles, L.K.; Chaves, A. |
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Title |
Strain and stacking registry effects on the hyperbolicity of exciton polaritons in few-layer black phosphorus |
Type |
A1 Journal article |
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Year |
2024 |
Publication |
Physical review B |
Abbreviated Journal |
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Volume |
109 |
Issue |
24 |
Pages |
245413-245419 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
We analyze, from first -principles calculations, the excitonic properties of monolayer black phosphorus (BP) under strain, as well as of bilayer BP with different stacking registries, as a base platform for the observation and use of hyperbolic polaritons. In the unstrained case, our results confirm the in -plane hyperbolic behavior of polaritons coupled to the ground -state excitons in both mono- and bilayer systems, as observed in recent experiments. With strain, we reveal that the exciton-polariton hyperbolicity in monolayer BP is enhanced (reduced) by compressive (tensile) strain in the zig-zag direction of the crystal. In the bilayer case, different stacking registries are shown to exhibit hyperbolic exciton polaritons with different dispersion, while also peaking at different frequencies. This renders both mechanical stress and stacking registry control as practical tools for tuning physical properties of hyperbolic exciton polaritons in black phosphorus, which facilitates detection and further optoelectronic use of these quasiparticles. |
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Wos |
001247621000008 |
Publication Date |
2024-06-10 |
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Edition |
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ISSN |
2469-9969; 2469-9950 |
ISBN |
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Additional Links |
UA library record; WoS full record |
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Impact Factor |
3.7 |
Times cited |
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Open Access |
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Notes |
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Approved |
Most recent IF: 3.7; 2024 IF: 3.836 |
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Call Number |
UA @ admin @ c:irua:206631 |
Serial |
9316 |
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Permanent link to this record |
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Author |
Aierken, Y.; Çakır, D.; Sevik, C.; Peeters, F.M. |
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Title |
Thermal properties of black and blue phosphorenes from a first-principles quasiharmonic approach |
Type |
A1 Journal article |
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Year |
2015 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
92 |
Issue |
92 |
Pages |
081408 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Different allotropes of phosphorene are possible of which black and blue phosphorus are the most stable. While blue phosphorus has isotropic properties, black phosphorus is strongly anisotropic in its electronic and optical properties due to its anisotropic crystal structure. In this work, we systematically investigated the lattice thermal properties of black and blue phosphorene by using first-principles calculations based on the quasiharmonic approximation approach. Similar to the optoelectronic and electronic properties, we predict that black phosphorene has highly anisotropic thermal properties, in contrast to the blue phase. The linear thermal expansion coefficients along the zigzag and armchair direction differ up to 20% in black phosphorene. The armchair direction of black phosphorene is more expandable as compared to the zigzag direction and the biaxial expansion of blue phosphorene under finite temperature. Our comparative analysis reveals that the inclusion of finite-temperature effects makes the blue phase thermodynamically more stable over the black phase above 135 K. |
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Place of Publication |
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Language |
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Wos |
000359860700005 |
Publication Date |
2015-08-19 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1098-0121 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.836 |
Times cited |
124 |
Open Access |
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Notes |
This work was supported by the Flemish Science Founda- tion (FWO-Vl) and the Methusalem foundation of the Flem- ish government. Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Comput- ing Center (TR-Grid e-Infrastructure), and HPC infrastructure of the University of Antwerp (CalcUA), a division of the Flemish Supercomputer Center (VSC), which is funded by the Hercules foundation. C.S. acknowledges the support from Anadolu University (BAP-1407F335), and Turkish Academy of Sciences (TUBA-GEBIP). |
Approved |
Most recent IF: 3.836; 2015 IF: 3.736 |
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Call Number |
c:irua:127754 |
Serial |
4034 |
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Permanent link to this record |
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Author |
Çakir, D.; Sevik, C.; Peeters, F.M. |
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Title |
Significant effect of stacking on the electronic and optical properties of few-layer black phosphorus |
Type |
A1 Journal article |
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Year |
2015 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
92 |
Issue |
92 |
Pages |
165406 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
The effect of the number of stacking layers and the type of stacking on the electronic and optical properties of bilayer and trilayer black phosphorus are investigated by using first-principles calculations within the framework of density functional theory. We find that inclusion of many-body effects (i.e., electron-electron and electron-hole interactions) modifies strongly both the electronic and optical properties of black phosphorus. While trilayer black phosphorus with a particular stacking type is found to be a metal by using semilocal functionals, it is predicted to have an electronic band gap of 0.82 eV when many-body effects are taken into account within the G(0)W(0) scheme. Though different stacking types result in similar energetics, the size of the band gap and the optical response of bilayer and trilayer phosphorene are very sensitive to the number of layers and the stacking type. Regardless of the number of layers and the type of stacking, bilayer and trilayer black phosphorus are direct band gap semiconductors whose band gaps vary within a range of 0.3 eV. Stacking arrangements that are different from the ground state structure in both bilayer and trilayer black phosphorus exhibit significant modified valence bands along the zigzag direction and result in larger hole effective masses. The optical gap of bilayer (trilayer) black phosphorus varies by 0.4 (0.6) eV when changing the stacking type. The calculated binding energy of the bound exciton hardly changes with the type of stacking and is found to be 0.44 (0.30) eV for bilayer (trilayer) phosphorous. |
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Place of Publication |
Lancaster, Pa |
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Wos |
000362435300005 |
Publication Date |
2015-10-08 |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1098-0121; 1550-235x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.836 |
Times cited |
127 |
Open Access |
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Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem foundation of the Flemish government. Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure), and HPC infrastructure of the University of Antwerp (CalcUA) a division of the Flemish Supercomputer Center (VSC), which is funded by the Hercules foundation. C.S. acknowledges support from Turkish Academy of Sciences (TUBA-GEBIP). ; |
Approved |
Most recent IF: 3.836; 2015 IF: 3.736 |
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Call Number |
UA @ lucian @ c:irua:128320 |
Serial |
4242 |
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Permanent link to this record |
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Author |
Michel, K.H.; Çakir, D.; Sevik, C.; Peeters, F.M. |
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Title |
Piezoelectricity in two-dimensional materials : comparative study between lattice dynamics and ab initio calculations |
Type |
A1 Journal article |
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Year |
2017 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
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Volume |
95 |
Issue |
95 |
Pages |
125415 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
The elastic constant C-11 and piezoelectric stress constant e(1),(11) of two-dimensional (2D) dielectric materials comprising h-BN, 2H-MoS2, and other transition-metal dichalcogenides and dioxides are calculated using lattice dynamical theory. The results are compared with corresponding quantities obtained with ab initio calculations. We identify the difference between clamped-ion and relaxed-ion contributions with the dependence on inner strains which are due to the relative displacements of the ions in the unit cell. Lattice dynamics allows us to express the inner-strain contributions in terms of microscopic quantities such as effective ionic charges and optoacoustical couplings, which allows us to clarify differences in the piezoelectric behavior between h-BN and MoS2. Trends in the different microscopic quantities as functions of atomic composition are discussed. |
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Corporate Author |
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Thesis |
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Publisher |
American Physical Society |
Place of Publication |
New York, N.Y |
Editor |
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Language |
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Wos |
000396013400005 |
Publication Date |
2017-03-11 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2469-9969; 2469-9950 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.836 |
Times cited |
29 |
Open Access |
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Notes |
; The authors acknowledge useful discussions with L. Wirtz and A. Molina-Sanchez. This work was supported by the Methusalem program and the Fonds voor Wetenschappelijk Onderzoek-Vlaanderen. Computational resources were provided by HPC infrastructure of the University of Antwerp (CalcUA), a division of the Flemish Supercomputer Center (VSC), which is funded by the Hercules foundation. ; |
Approved |
Most recent IF: 3.836 |
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Call Number |
UA @ lucian @ c:irua:142444 |
Serial |
4603 |
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Permanent link to this record |
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Author |
Yagmurcukardes, M.; Sevik, C.; Peeters, F.M. |
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Title |
Electronic, vibrational, elastic, and piezoelectric properties of monolayer Janus MoSTe phases: A first-principles study |
Type |
A1 Journal article |
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Year |
2019 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
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Volume |
100 |
Issue |
4 |
Pages |
045415 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
By performing density functional theory based first-principles calculations, the electronic, vibrational, elastic, and piezoelectric properties of two dynamically stable crystal phases of monolayer Janus MoSTe, namely 1H-MoSTe and 1T'-MoSTe, are investigated. Vibrational frequency analysis reveals that the other possible crystal structure, 1T-MoSTe, of this Janus monolayer does not exhibit dynamical stability. The 1H-MoSTe phase is found to be an indirect band-gap semiconductor while 1T'-MoSTe is predicted as small-gap semiconductor. Notably, in contrast to the direct band-gap nature of monolayers 1H-MoS2 and 1H-MoTe2, 1H-MoSTe is found to be an indirect gap semiconductor driven by the induced surface strains on each side of the structure. The calculated Raman spectrum of each structure shows unique character enabling us to clearly distinguish the stable crystal phases via Raman measurements. The systematic piezoelectric stress and strain coefficient analysis reveals that out-of-plane piezoelectricity appears in 1H-MoSTe and the noncentral symmetric 1T'-MoSTe has large piezoelectric coefficients. Static total-energy calculations show clearly that the formation of 1T'-MoSTe is feasible by using 1T'-MoTe2 as a basis monolayer. Therefore, we propose that the Janus MoSTe structure can be fabricated in two dynamically stable phases which possess unique electronic, dynamical, and piezoelectric properties. |
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Thesis |
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Place of Publication |
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Language |
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Wos |
000476687800003 |
Publication Date |
2019-07-19 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2469-9969; 2469-9950 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.836 |
Times cited |
128 |
Open Access |
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Notes |
; Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure). This work was supported by the Flemish Science Foundation (FWO-Vl) by a postdoctoral fellowship (M.Y.). ; |
Approved |
Most recent IF: 3.836 |
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Call Number |
UA @ admin @ c:irua:161899 |
Serial |
5411 |
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Permanent link to this record |
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Author |
Demiroglu, I.; Sevik, C. |
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Title |
Extraordinary negative thermal expansion of two-dimensional nitrides : a comparative ab initio study of quasiharmonic approximation and molecular dynamics simulations |
Type |
A1 Journal article |
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Year |
2021 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
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Volume |
103 |
Issue |
8 |
Pages |
085430 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Thermal expansion behavior of two-dimensional (2D) nitrides and graphene were studied by ab initio molecular dynamics (MD) simulations as well as quasiharmonic approximation (QHA). Anharmonicity of the acoustic phonon modes are related to the unusual negative thermal expansion (NTE) behavior of the nitrides. Our results also hint that direct ab initio MD simulations are a more elaborate method to investigate thermal expansion behavior of 2D materials than the QHA. Nevertheless, giant NTE coefficients are found for h-GaN and h-AlN within the covered temperature range 100-600 K regardless of the chosen computational method. This unusual NTE of 2D nitrides is reasoned with the out-of-plane oscillations related to the rippling behavior of the monolayers. |
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Place of Publication |
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Wos |
000620346100007 |
Publication Date |
2021-02-22 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2469-9969; 2469-9950 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.836 |
Times cited |
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Open Access |
OpenAccess |
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Notes |
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Approved |
Most recent IF: 3.836 |
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Call Number |
UA @ admin @ c:irua:176671 |
Serial |
7956 |
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Permanent link to this record |
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Author |
Alyörük, M.M.; Aierken, Y.; Çakır, D.; Peeters, F.M.; Sevik, C. |
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Title |
Promising Piezoelectric Performance of Single Layer Transition-Metal Dichalcogenides and Dioxides |
Type |
A1 Journal article |
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Year |
2015 |
Publication |
The journal of physical chemistry: C : nanomaterials and interfaces |
Abbreviated Journal |
J Phys Chem C |
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Volume |
119 |
Issue |
119 |
Pages |
23231-23237 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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Abstract |
Piezoelectricity is a unique material property that allows one to convert mechanical energy into electrical one or vice versa. Transition metal dichalcogenides (TMDC) and transition metal dioxides (TMDO) are expected to have great potential for piezoelectric device applications due to their noncentrosymmetric and two-dimensional crystal structure. A detailed theoretical investigation of the piezoelectric stress (e 11 ) and piezoelectric strain (d 11 ) coefficients of single layer TMDCs and TMDOs with chemical formula MX 2 (where M= Cr, Mo, W, Ti, Zr, Hf, Sn and X = O, S, Se, Te) is presented by using first-principles calculations based on density func- tional theory. We predict that not only the Mo- and W-based members of this family but also the other materials with M= Cr, Ti, Zr and Sn exhibit highly promising piezoelectric properties. CrTe 2 has the largest e 11 and d 11 coefficients among the group VI elements (i.e., Cr, Mo, and W). In addition, the relaxed-ion e 11 and d 11 coefficients of SnS 2 are almost the same as those of CrTe 2 . Furthermore, TiO 2 and ZrO 2 pose comparable or even larger e 11 coefficients as compared to Mo- and W-based TMDCs and TMDOs. Our calculations reveal that TMDC and TMDO structures are strong candidates for future atomically thin piezoelectric applications such as transducers, sensors, and energy harvesting devices due to their piezoelectric coefficients that are comparable (even larger) to currently used bulk piezoelectric materials. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Language |
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Wos |
000362702100054 |
Publication Date |
2015-09-14 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1932-7447 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.536 |
Times cited |
134 |
Open Access |
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Notes |
M.M.A and C.S. acknowledges the support from Scientific and Technological Research Council of Turkey (TUBITAK- 113F333). C.S. acknowledges support from Anadolu University (BAP-1407F335, -1505F200), and Turkish Academy of Sciences (TUBA-GEBIP). Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure), and HPC infrastructure of the University of Antwerp (CalcUA) a division of the Flemish Supercomputer Center (VSC), which is funded by the Hercules foundation. |
Approved |
Most recent IF: 4.536; 2015 IF: 4.772 |
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Call Number |
c:irua:129418 |
Serial |
4035 |
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Permanent link to this record |
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Author |
Sevik, C.; Çakir, D.; Gulseren, O.; Peeters, F.M. |
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Title |
Peculiar piezoelectric properties of soft two-dimensional materials |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
The journal of physical chemistry: C : nanomaterials and interfaces |
Abbreviated Journal |
J Phys Chem C |
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Volume |
120 |
Issue |
120 |
Pages |
13948-13953 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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Abstract |
Group II-VI semiconductor honeycomb monolayers have a noncentrosymmetric crystal structure and therefore are expected to be important for nano piezoelectric device applications. This motivated us to perform first principles calculations based on density functional theory to unveil the piezoelectric properties (i.e., piezoelectric stress (e(11)) and piezoelectric strain (d(11)) coefficients) of these monolayer materials with chemical formula MX (where M = Be, Mg, Ca, Sr, Ba, Zr, Cd and X = S, Se, Te). We found that these two-dimensional materials have peculiar piezoelectric properties with d(11) coefficients 1 order of magnitude larger than those of commercially utilized bulk materials. A clear trend in their piezoelectric properties emerges, which |
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Corporate Author |
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Publisher |
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Place of Publication |
Washington, D.C. |
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Wos |
000379457000010 |
Publication Date |
2016-06-09 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1932-7447; 1932-7455 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.536 |
Times cited |
39 |
Open Access |
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Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl), the Methusalem foundation of the Flemish government and the Bilateral program FWO-TUBITAK between Flanders and Turkey. We acknowledge the support from the Scientific and Technological Research Council of Turkey (TUBITAK-115F024). Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure), and HPC infrastructure of the University of Antwerp (Cal-cUA) a division of the Flemish Supercomputer Center (VSC), which is funded by the Hercules foundation. C.S. acknowledges the support from the Scientific and Technological Research Council of Turkey (TUBITAK-113F333) and the support from Anadolu University (BAP-1407F335, -1505F200), and the Turkish Academy of Sciences (TUBA-GEBIP). ; |
Approved |
Most recent IF: 4.536 |
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Call Number |
UA @ lucian @ c:irua:134948 |
Serial |
4222 |
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Permanent link to this record |
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Author |
Demiroglu, I.; Karaaslan, Y.; Kocabas, T.; Keceli, M.; Vazquez-Mayagoitia, A.; Sevik, C. |
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Title |
Computation of the thermal expansion coefficient of graphene with Gaussian approximation potentials |
Type |
A1 Journal article |
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Year |
2021 |
Publication |
Journal Of Physical Chemistry C |
Abbreviated Journal |
J Phys Chem C |
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Volume |
125 |
Issue |
26 |
Pages |
14409-14415 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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Abstract |
Direct experimental measurement of thermal expansion coefficient without substrate effects is a challenging task for two-dimensional (2D) materials, and its accurate estimation with large-scale ab initio molecular dynamics is computationally very expensive. Machine learning-based interatomic potentials trained with ab initio data have been successfully used in molecular dynamics simulations to decrease the computational cost without compromising the accuracy. In this study, we investigated using Gaussian approximation potentials to reproduce the density functional theory-level accuracy for graphene within both lattice dynamical and molecular dynamical methods, and to extend their applicability to larger length and time scales. Two such potentials are considered, GAP17 and GAP20. GAP17, which was trained with pristine graphene structures, is found to give closer results to density functional theory calculations at different scales. Further vibrational and structural analyses verify that the same conclusions can be deduced with density functional theory level in terms of the reasoning of the thermal expansion behavior, and the negative thermal expansion behavior is associated with long-range out-of-plane phonon vibrations. Thus, it is argued that the enabled larger system sizes by machine learning potentials may even enhance the accuracy compared to small-size-limited ab initio molecular dynamics. |
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Place of Publication |
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Language |
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Wos |
000672734100027 |
Publication Date |
2021-06-24 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1932-7447; 1932-7455 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.536 |
Times cited |
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Open Access |
OpenAccess |
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Notes |
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Approved |
Most recent IF: 4.536 |
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Call Number |
UA @ admin @ c:irua:179850 |
Serial |
7719 |
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Permanent link to this record |
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Author |
Korkmaz, Y.A.; Bulutay, C.; Sevik, C. |
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Title |
k · p parametrization and linear and circular dichroism in strained monolayer (Janus) transition metal dichalcogenides from first-principles |
Type |
A1 Journal article |
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Year |
2021 |
Publication |
Journal Of Physical Chemistry C |
Abbreviated Journal |
J Phys Chem C |
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Volume |
125 |
Issue |
13 |
Pages |
7439-7450 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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Abstract |
Semiconductor monolayer transition metal dichalcogenides (TMDs) have brought a new paradigm by introducing optically addressable valley degree of freedom. Concomitantly, their high flexibility constitutes a unique platform that links optics to mechanics via valleytronics. With the intention to expedite the research in this direction, we investigated ten TMDs, namely MoS2, MoSe2, MoTe2, WS2, WSe2, WTe2, MoSSe, MoSeTe, WSSe, and WSeTe, which particularly includes their so-called janus types (JTMDs). First, we obtained their electronic band structures using regular and hybrid density functional theory (DFT) calculations in the presence of the spin-orbit coupling and biaxial or uniaxial strain. Our DFT results indicated that against the expectations based on their reported piezoelectric behavior, JTMDs typically interpolated between the standard band properties of the constituent TMDs without producing a novel feature. Next, by fitting to our DFT data we generated both spinless and spinful k center dot p parameter sets which are quite accurate over the K valley where the optical activity occurs. As an important application of this parametrization, we considered the circular and linear dichroism under strain. Among the studied (J)TMDs, WTe2 stood out with its largest linear dichroism under uniaxial strain because of its narrower band gap and large K valley uniaxial deformation potential. This led us to suggest WTe2 monolayer membranes for optical polarization-based strain measurements, or conversely, as strain tunable optical polarizers. |
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Wos |
000639044400045 |
Publication Date |
2021-03-26 |
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Series Editor |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1932-7447; 1932-7455 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.536 |
Times cited |
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Open Access |
OpenAccess |
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Notes |
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Approved |
Most recent IF: 4.536 |
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Call Number |
UA @ admin @ c:irua:178264 |
Serial |
8136 |
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Permanent link to this record |
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Author |
Karaaslan, Y.; Yapicioglu, H.; Sevik, C. |
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Title |
Assessment of Thermal Transport Properties of Group-III Nitrides: A Classical Molecular Dynamics Study with Transferable Tersoff-Type Interatomic Potentials |
Type |
A1 Journal article |
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Year |
2020 |
Publication |
Physical Review Applied |
Abbreviated Journal |
Phys Rev Appl |
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Volume |
13 |
Issue |
3 |
Pages |
034027 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
In this study, by means of classical molecular dynamics simulations, we investigate the thermal-transport properties of hexagonal single-layer, zinc-blend, and wurtzite phases of BN, AlN, and GaN crystals, which are very promising for the application and design of high-quality electronic devices. With this in mind, we generate fully transferable Tersoff-type empirical interatomic potential parameter sets by utilizing an optimization procedure based on particle-swarm optimization. The predicted thermal properties as well as the structural, mechanical, and vibrational properties of all materials are in very good agreement with existing experimental and first-principles data. The impact of isotopes on thermal transport is also investigated and between approximately 10 and 50% reduction in phonon thermal transport with random isotope distribution is observed in BN and GaN crystals. Our investigation distinctly shows that the generated parameter sets are fully transferable and very useful in exploring the thermal properties of systems containing these nitrides. |
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Place of Publication |
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Wos |
000518820200003 |
Publication Date |
2020-03-10 |
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Series Editor |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2331-7019 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.6 |
Times cited |
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Open Access |
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Notes |
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Approved |
Most recent IF: 4.6; 2020 IF: 4.808 |
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Call Number |
UA @ admin @ c:irua:193766 |
Serial |
7508 |
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Permanent link to this record |
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Author |
Akande, S.O.; Samanta, B.; Sevik, C.; Cakir, D. |
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Title |
First-principles investigation of mechanical and thermal properties of M Al B (M = Mo, W), Cr₂ AlB₂, and Ti₂ In B₂ |
Type |
A1 Journal article |
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Year |
2023 |
Publication |
Physical review applied |
Abbreviated Journal |
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Volume |
20 |
Issue |
4 |
Pages |
044064-17 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
The atomically laminated layered ternary transition-metal borides (the MAB phases) have demonstrated outstanding properties and have been applied in various fields. Understanding their thermal and mechanical properties is critical to determining their applicability in various fields such as high-temperature applications. To achieve this, we conducted first-principles calculations based on density-functional theory and the quasiharmonic approximation to determine the thermal expansion coefficients, Gruneisen parameters, bulk moduli, hardness, thermal conductivity, electron-phonon coupling parameters, and the structural and vibrational properties of MoAlB, WAlB, Cr2AlB2, and Ti2InB2. We found varying degrees of anisotropy in the thermal expansion and mechanical properties in spite of similarities in their crystal structures. MoAlB has a mild degree of anisotropy in its thermal expansion coefficient (TEC), while Cr2AlB2 and WAlB display the highest level of TEC anisotropy. We assessed various empirical models to calculate hardness and thermal conductivity, and correlated the calculated values with the material properties such as elastic moduli, Gruneisen parameter, Debye temperature, and type of bonding. Owing to their higher Gruneisen parameters, implying a greater degree of anharmonicity in lattice vibrations and lower phonon group velocities, MoAlB and WAlB have significantly lower lattice thermal conductivity values than those of Cr2AlB2 and Ti2InB2. The hardness and lattice thermal conductivity of MAB phases can be predicted with high accuracy if one utilizes an appropriate model. |
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Wos |
001106456600003 |
Publication Date |
2023-10-25 |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2331-7019 |
ISBN |
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Additional Links |
UA library record; WoS full record |
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Impact Factor |
4.6 |
Times cited |
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Open Access |
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Notes |
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Approved |
Most recent IF: 4.6; 2023 IF: 4.808 |
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Call Number |
UA @ admin @ c:irua:202078 |
Serial |
9037 |
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Permanent link to this record |
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Author |
Çakir, D.; Sevik, C.; Peeters, F.M. |
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Title |
Engineering electronic properties of metal-MoSe2 interfaces using self-assembled monolayers |
Type |
A1 Journal article |
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Year |
2014 |
Publication |
Journal of materials chemistry C : materials for optical and electronic devices |
Abbreviated Journal |
J Mater Chem C |
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Volume |
2 |
Issue |
46 |
Pages |
9842-9849 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Metallic contacts are critical components of electronic devices and the presence of a large Schottky barrier is detrimental for an optimal device operation. Here, we show by using first-principles calculations that a self-assembled monolayer (SAM) of polar molecules between the metal electrode and MoSe2 monolayer is able to convert the Schottky contact into an almost Ohmic contact. We choose -CH3 and -CF3 terminated short-chain alkylthiolate (i.e. SCH3 and fluorinated alkylthiolates (SCF3)) based SAMs to test our approach. We consider both high (Au) and low (Sc) work function metals in order to thoroughly elucidate the role of the metal work function. In the case of Sc, the Fermi level even moves into the conduction band of the MoSe2 monolayer upon SAM insertion between the metal surface and the MoSe2 monolayer, and hence possibly switches the contact type from Schottky to Ohmic. The usual Fermi level pinning at the metal-transition metal dichalcogenide (TMD) contact is shown to be completely removed upon the deposition of a SAM. Systematic analysis indicates that the work function of the metal surface and the energy level alignment between the metal electrode and the TMD monolayer can be tuned significantly by using SAMs as a buffer layer. These results clearly indicate the vast potential of the proposed interface engineering to modify the physical and chemical properties of MoSe2. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000344998700007 |
Publication Date |
2014-10-16 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
|
Edition |
|
|
|
ISSN |
2050-7526;2050-7534; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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|
Impact Factor |
5.256 |
Times cited |
22 |
Open Access |
|
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|
Notes |
; Part of this work is supported by the Flemish Science Foundation (FWO-VI) and the Methusalem foundation of the Flemish Government. Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure). D. C. is supported by a FWO Pegasus-short Marie Curie Fellowship. C. S. acknowledges the support from Scientific and Technological Research Council of Turkey (TUBITAK 113F096), Anadolu University (BAP-1306F281, -1404F158) and Turkish Academy of Science (TUBA). ; |
Approved |
Most recent IF: 5.256; 2014 IF: 4.696 |
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Call Number |
UA @ lucian @ c:irua:122157 |
Serial |
1046 |
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Permanent link to this record |
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Author |
Yorulmaz, U.; Šabani, D.; Sevik, C.; Milošević, M.V. |
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Title |
Goodenough-Kanamori-Anderson high-temperature ferromagnetism in tetragonal transition-metal xenes |
Type |
A1 Journal article |
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Year |
2024 |
Publication |
2D materials |
Abbreviated Journal |
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|
Volume |
11 |
Issue |
3 |
Pages |
035013-10 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Seminal Goodenough-Kanamori-Anderson (GKA) rules provide an inceptive understanding of the superexchange interaction of two magnetic metal ions bridged with an anion, and suggest fostered ferromagnetic interaction for orthogonal bridging bonds. However, there are no examples of two-dimensional (2D) materials with structure that optimizes the GKA arguments towards enhanced ferromagnetism and its critical temperature. Here we reveal that an ideally planar GKA ferromagnetism is indeed stable in selected tetragonal transition-metal xenes (tTMXs), with Curie temperature above 300 K found in CrC and MnC. We provide the general orbitally-resolved analysis of magnetic interactions that supports the claims and sheds light at the mechanisms dominating the magnetic exchange process in these structures. Furthermore, we propose the set of three GKA-like rules that will guarantee room temperature ferromagetnism. With recent advent of epitaxially-grown tetragonal 2D materials, our findings earmark tTMXs for facilitated spintronic and magnonic applications, or as a desirable magnetic constituent of functional 2D heterostructures. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
001208053200001 |
Publication Date |
2024-04-12 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
|
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ISSN |
2053-1583 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
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Impact Factor |
5.5 |
Times cited |
|
Open Access |
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Notes |
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Approved |
Most recent IF: 5.5; 2024 IF: 6.937 |
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Call Number |
UA @ admin @ c:irua:205464 |
Serial |
9153 |
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Permanent link to this record |
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Author |
Bekaert, J.; Sevik, C.; Milošević, M.V. |
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Title |
First-principles exploration of superconductivity in MXenes |
Type |
A1 Journal article |
|
Year |
2020 |
Publication |
Nanoscale |
Abbreviated Journal |
Nanoscale |
|
|
Volume |
12 |
Issue |
|
Pages |
17354-17361 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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Abstract |
MXenes are an emerging class of two-dimensional materials, which in their thinnest limit consist of a monolayer of carbon or nitrogen (X) sandwiched between two transition metal (M) layers. We have systematically searched for superconductivity among MXenes for a range of transition metal elements, based on a full first-principles characterization in combination with the Eliashberg formalism. Thus, we identified six superconducting MXenes: three carbides (Mo2C, W2C and Sc2C) and three nitrides (Mo2N, W2N and Ta2N). The highest critical temperature of similar to 16 K is found in Mo2N, for which a successful synthesis method has been established [Urbankowskiet al.,Nanoscale, 2017,9, 17722-17730]. Moreover, W2N presents a novel case of competing superconducting and charge density wave phases. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000563481700017 |
Publication Date |
2020-08-07 |
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Series Editor |
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Series Title |
|
Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
2040-3364 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
6.7 |
Times cited |
15 |
Open Access |
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Notes |
; This work is supported by The Scientific and Technological Research Council of Turkey (TUBITAK) under the contract number COST-118F187, the Air Force Office of Scientific Research under award number FA9550-19-1-7048, by Research Foundation-Flanders (FWO) and the University of Antwerp (BOF). The collaboration was fostered by COST action NANOCOHYBRI (CA16218). Computational resources were provided by the High Performance and Grid Computing Center (TRGrid e-Infrastructure) of TUBITAK ULAKBIM, the National Center for High Performance Computing (UHeM) of Istanbul Technical University, and by the VSC (Flemish Supercomputer Center), funded by the FWO and the Flemish Government – department EWI. J. B. acknowledges support of a postdoctoral fellowship of the FWO. ; |
Approved |
Most recent IF: 6.7; 2020 IF: 7.367 |
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Call Number |
UA @ admin @ c:irua:171988 |
Serial |
6521 |
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Permanent link to this record |
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Author |
Bekaert, J.; Sevik, C.; Milošević, M.V. |
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Title |
Enhancing superconductivity in MXenes through hydrogenation |
Type |
A1 Journal article |
|
Year |
2022 |
Publication |
Nanoscale |
Abbreviated Journal |
Nanoscale |
|
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Volume |
14 |
Issue |
27 |
Pages |
9918-9924 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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Abstract |
Two-dimensional transition metal carbides and nitrides (MXenes) are an emerging class of atomically-thin superconductors, whose characteristics are highly prone to tailoring by surface functionalization. Here we explore the use of hydrogen adatoms to enhance phonon-mediated superconductivity in MXenes, based on first-principles calculations combined with Eliashberg theory. We first demonstrate the stability of three different structural models of hydrogenated Mo- and W-based MXenes. Particularly high critical temperatures of over 30 K are obtained for hydrogenated Mo2N and W2N. Several mechanisms responsible for the enhanced electron-phonon coupling are uncovered, namely (i) hydrogen-induced changes in the phonon spectrum of the host MXene, (ii) emerging hydrogen-based phonon modes, and (iii) charge transfer from hydrogen to the MXene layer, boosting the density of states at the Fermi level. Finally, we demonstrate that hydrogen adatoms are moreover able to induce superconductivity in MXenes that are not superconducting in pristine form, such as Nb2C. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000820350600001 |
Publication Date |
2022-06-27 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
|
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ISSN |
2040-3364; 2040-3372 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
6.7 |
Times cited |
2 |
Open Access |
OpenAccess |
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Notes |
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Approved |
Most recent IF: 6.7 |
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Call Number |
UA @ admin @ c:irua:189580 |
Serial |
7155 |
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Permanent link to this record |
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Author |
Kocabas, T.; Keceli, M.; Vazquez-Mayagoitia, A.; Sevik, C. |
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Title |
Gaussian approximation potentials for accurate thermal properties of two-dimensional materials |
Type |
A1 Journal article |
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Year |
2023 |
Publication |
Nanoscale |
Abbreviated Journal |
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Volume |
15 |
Issue |
19 |
Pages |
8772-8780 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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Abstract |
Two-dimensional materials (2DMs) continue to attract a lot of attention, particularly for their extreme flexibility and superior thermal properties. Molecular dynamics simulations are among the most powerful methods for computing these properties, but their reliability depends on the accuracy of interatomic interactions. While first principles approaches provide the most accurate description of interatomic forces, they are computationally expensive. In contrast, classical force fields are computationally efficient, but have limited accuracy in interatomic force description. Machine learning interatomic potentials, such as Gaussian Approximation Potentials, trained on density functional theory (DFT) calculations offer a compromise by providing both accurate estimation and computational efficiency. In this work, we present a systematic procedure to develop Gaussian approximation potentials for selected 2DMs, graphene, buckled silicene, and h-XN (X = B, Al, and Ga, as binary compounds) structures. We validate our approach through calculations that require various levels of accuracy in interatomic interactions. The calculated phonon dispersion curves and lattice thermal conductivity, obtained through harmonic and anharmonic force constants (including fourth order) are in excellent agreement with DFT results. HIPHIVE calculations, in which the generated GAP potentials were used to compute higher-order force constants instead of DFT, demonstrated the first-principles level accuracy of the potentials for interatomic force description. Molecular dynamics simulations based on phonon density of states calculations, which agree closely with DFT-based calculations, also show the success of the generated potentials in high-temperature simulations. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000976615200001 |
Publication Date |
2023-04-19 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2040-3364; 2040-3372 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
6.7 |
Times cited |
|
Open Access |
Not_Open_Access |
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Notes |
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Approved |
Most recent IF: 6.7; 2023 IF: 7.367 |
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Call Number |
UA @ admin @ c:irua:196722 |
Serial |
8873 |
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Permanent link to this record |
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Author |
Sevik, C.; Bekaert, J.; Milošević, M.V. |
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Title |
Superconductivity in functionalized niobium-carbide MXenes |
Type |
A1 Journal article |
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Year |
2023 |
Publication |
Nanoscale |
Abbreviated Journal |
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Volume |
15 |
Issue |
19 |
Pages |
8792-8799 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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Abstract |
We detail the effects of Cl and S functionalization on the superconducting properties of layered (bulk) and monolayer niobium carbide (Nb2C) MXene crystals, based on first-principles calculations combined with Eliashberg theory. For bulk layered Nb2CCl2, the calculated superconducting transition temperature (T-c) is in very good agreement with the recently measured value of 6 K. We show that T-c is enhanced to 10 K for monolayer Nb2CCl2, due to an increase in the density of states at the Fermi level, and the corresponding electron-phonon coupling. We further demonstrate feasible gate- and strain-induced enhancements of T-c for both bulk-layered and monolayer Nb2CCl2 crystals, resulting in T-c values of around 38 K. In the S-functionalized Nb2CCl2 crystals, our calculations reveal the importance of phonon softening in understanding their superconducting properties. Finally, we predict that Nb3C2S2 in bulk-layered and monolayer forms is also superconducting, with a T-c of around 28 K. Considering that Nb2C is not superconducting in pristine form, our findings promote functionalization as a pathway towards robust superconductivity in MXenes. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000976973900001 |
Publication Date |
2023-04-11 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
|
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ISSN |
2040-3364; 2040-3372 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
6.7 |
Times cited |
|
Open Access |
OpenAccess |
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Notes |
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Approved |
Most recent IF: 6.7; 2023 IF: 7.367 |
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Call Number |
UA @ admin @ c:irua:196711 |
Serial |
8938 |
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Permanent link to this record |
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Author |
Yorulmaz, U.; Demiroglu, I.; Cakir, D.; Gulseren, O.; Sevik, C. |
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Title |
A systematicalab-initioreview of promising 2D MXene monolayers towards Li-ion battery applications |
Type |
A1 Journal article |
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Year |
2020 |
Publication |
JPhys Energy |
Abbreviated Journal |
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Volume |
2 |
Issue |
3 |
Pages |
032006 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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Abstract |
Two-dimensional materials have been attracting increasing interests because of their outstanding properties for Lithium-ion battery applications. In particular, a material family called MXenes (Mn+1Cn, where n = 1, 2, 3) have been recently attracted immense interest in this respect due to their incomparable fast-charging properties and high capacity promises. In this article, we review the state-of-the-art computational progress on Li-ion battery applications of MXene materials in accordance with our systematical DFT calculations. Structural, mechanical, dynamical, and electrical properties of 20 distinct MXene (M: Sc, Ti, V, Cr, Nb, Mo, Hf, Ta, W, and Zr) have been discussed. The battery performances of these MXene monolayers are further investigated by Li-ion binding energies, open circuit voltage values, and Li migration energy barriers. The experimental and theoretical progress up to date demonstrates particularly the potential of non-terminated or pristine MXene materials in Li ion-storage applications. Stability analyses show most of the pristine MXenes should be achievable, however susceptible to the development progress on the experimental growth procedures. Among pristine MXenes, Ti2C, V2C, Sc2C, and Zr2C compounds excel with their high charge/discharge rate prospect due to their extremely low Li diffusion energy barriers. Considering also their higher predicted gravimetric capacities, Sc, Ti, V, and Zr containing MXenes are more promising for their utilization in energy storage applications. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000569868600001 |
Publication Date |
2020-07-16 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2515-7655 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
6.9 |
Times cited |
|
Open Access |
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Notes |
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Approved |
Most recent IF: 6.9; 2020 IF: NA |
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Call Number |
UA @ admin @ c:irua:193748 |
Serial |
7399 |
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Permanent link to this record |
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Author |
Sevik, C.; Wallbank, J.R.; Gulseren, O.; Peeters, F.M.; Çakir, D. |
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Title |
Gate induced monolayer behavior in twisted bilayer black phosphorus |
Type |
A1 Journal article |
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Year |
2017 |
Publication |
2D materials |
Abbreviated Journal |
2D Mater |
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Volume |
4 |
Issue |
3 |
Pages |
035025 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Optical and electronic properties of black phosphorus strongly depend on the number of layers and type of stacking. Using first-principles calculations within the framework of density functional theory, we investigate the electronic properties of bilayer black phosphorus with an interlayer twist angle of 90 degrees. These calculations are complemented with a simple (k) over right arrow . (p) over right arrow model which is able to capture most of the low energy features and is valid for arbitrary twist angles. The electronic spectrum of 90 degrees twisted bilayer black phosphorus is found to be x-y isotropic in contrast to the monolayer. However x-y anisotropy, and a partial return to monolayer-like behavior, particularly in the valence band, can be induced by an external out-of-plane electric field. Moreover, the preferred hole effective mass can be rotated by 90 degrees simply by changing the direction of the applied electric field. In particular, a +0.4 (-0.4) V angstrom(1) out-of-plane electric field results in a similar to 60% increase in the hole effective mass along the y (x) axis and enhances the m(y)*/m(x)* (m(x)*/m(y)*) ratio as much as by a factor of 40. Our DFT and (k) over right arrow . (p) over right arrow simulations clearly indicate that the twist angle in combination with an appropriate gate voltage is a novel way to tune the electronic and optical properties of bilayer phosphorus and it gives us a new degree of freedom to engineer the properties of black phosphorus based devices. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
IOP Publishing |
Place of Publication |
Bristol |
Editor |
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Language |
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Wos |
000406926600001 |
Publication Date |
2017-08-03 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2053-1583 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
6.937 |
Times cited |
13 |
Open Access |
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Notes |
; This work was supported by the bilateral project between the The Scientific and Technological Research Council of Turkey (TUBITAK) and FWO-Flanders, Flemish Science Foundation (FWO-Vl) and the Methusalem foundation of the Flemish government. Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TRGrid e-Infrastructure), and HPC infrastructure of the University of Antwerp (CalcUA) a division of the Flemish Supercomputer Center (VSC), which is funded by the Hercules foundation. We acknowledge the support from TUBITAK (Grant No. 115F024), ERC Synergy grant Hetero2D and the EU Graphene Flagship Project. We also thank Vladimir Fal'ko for helpful discussions. ; |
Approved |
Most recent IF: 6.937 |
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Call Number |
UA @ lucian @ c:irua:145151 |
Serial |
4717 |
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Permanent link to this record |
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Author |
Çakir, D.; Sevik, C.; Gulseren, O.; Peeters, F.M. |
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Title |
Mo2C as a high capacity anode material: a first-principles study |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
Journal of materials chemistry A : materials for energy and sustainability |
Abbreviated Journal |
J Mater Chem A |
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Volume |
4 |
Issue |
16 |
Pages |
6029-6035 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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Abstract |
The adsorption and diffusion of Li, Na, K and Ca atoms on a Mo2C monolayer are systematically investigated by using first principles methods. We found that the considered metal atoms are strongly bound to the Mo2C monolayer. However, the adsorption energies of these alkali and earth alkali elements decrease as the coverage increases due to the enhanced repulsion between the metal ions. We predict a significant charge transfer from the ad-atoms to the Mo2C monolayer, which indicates clearly the cationic state of the metal atoms. The metallic character of both pristine and doped Mo2C ensures a good electronic conduction that is essential for an optimal anode material. Low migration energy barriers are predicted as small as 43 meV for Li, 19 meV for Na and 15 meV for K, which result in the very fast diffusion of these atoms on Mo2C. For Mo2C, we found a storage capacity larger than 400 mA h g(-1) by the inclusion of multilayer adsorption. Mo2C expands slightly upon deposition of Li and Na even at high concentrations, which ensures the good cyclic stability of the atomic layer. The calculated average voltage of 0.68 V for Li and 0.30 V for Na ions makes Mo2C attractive for low charging voltage applications. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Cambridge |
Editor |
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Language |
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Wos |
000374790700033 |
Publication Date |
2016-03-18 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2050-7488; 2050-7496 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
8.867 |
Times cited |
202 |
Open Access |
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Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem foundation of the Flemish government. Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure), and HPC infrastructure of the University of Antwerp (CalcUA) a division of the Flemish Supercomputer Center (VSC), which is funded by the Hercules foundation. C. S. acknowledges the support from Turkish Academy of Sciences (TUBA-GEBIP). C. S acknowledges the support from Anadolu University (Grant No. 1407F335). We acknowledge the support from TUBITAK, The Scientific and Technological Research Council of Turkey (Grant No. 115F024). ; |
Approved |
Most recent IF: 8.867 |
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Call Number |
UA @ lucian @ c:irua:144763 |
Serial |
4669 |
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Permanent link to this record |
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Author |
Aierken, Y.; Sevik, C.; Gulseren, O.; Peeters, F.M.; Çakir, D. |
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Title |
MXenes/graphene heterostructures for Li battery applications : a first principles study |
Type |
A1 Journal article |
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Year |
2018 |
Publication |
Journal of materials chemistry A : materials for energy and sustainability |
Abbreviated Journal |
J Mater Chem A |
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Volume |
6 |
Issue |
5 |
Pages |
2337-2345 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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Abstract |
MXenes are the newest class of two-dimensional (2D) materials, and they offer great potential in a wide range of applications including electronic devices, sensors, and thermoelectric and energy storage materials. In this work, we combined the outstanding electrical conductivity, that is essential for battery applications, of graphene with MXene monolayers (M2CX2 where M = Sc, Ti, V and X = OH, O) to explore its potential in Li battery applications. Through first principles calculations, we determined the stable stacking configurations of M2CX2/graphene bilayer heterostructures and their Li atom intercalation by calculating the Li binding energy, diffusion barrier and voltage. We found that: (1) for the ground state stacking, the interlayer binding is strong, yet the interlayer friction is small; (2) Li binds more strongly to the O-terminated monolayer, bilayer and heterostructure MXene systems when compared with the OHterminated MXenes due to the H+ induced repulsion to the Li atoms. The binding energy of Li decreases as the Li concentration increases due to enhanced repulsive interaction between the positively charged Li ions; (3) Ti2CO2/graphene and V2CO2/graphene heterostructures exhibit large Li atom binding energies making them the most promising candidates for battery applications. When fully loaded with Li atoms, the binding energy is -1.43 eV per Li atom and -1.78 eV per Li atom for Ti2CO2/graphene and V2CO2/graphene, respectively. These two heterostructures exhibit a nice compromise between storage capacity and kinetics. For example, the diffusion barrier of Li in Ti2CO2/graphene is around 0.3 eV which is comparable to that of graphite. Additionally, the calculated average voltages are 1.49 V and 1.93 V for Ti2CO2/graphene and V2CO2/graphene structures, respectively; (4) a small change in the in-plane lattice parameters (<1%), interatomic bond lengths and interlayer distances (<0.5 angstrom) proves the stability of the heterostructures against Li intercalation, and the impending phase separation into constituent layers and capacity fading during charge-discharge cycles in real battery applications; (5) as compared to bare M2CX2 bilayers, M2CX2/graphene heterostructures have lower molecular mass, offering high storage capacity; (6) the presence of graphene ensures good electrical conductivity that is essential for battery applications. Given these advantages, Ti2CO2/graphene and V2CO2/graphene heterostructures are predicted to be promising for lithium-ion battery applications. |
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Cambridge |
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Wos |
000423981200049 |
Publication Date |
2018-01-02 |
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ISSN |
2050-7488; 2050-7496 |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
8.867 |
Times cited |
131 |
Open Access |
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Notes |
; This work was supported by the bilateral project between the Scientific and Technological Research Council of Turkey (TUBITAK) and FWO-Flanders, Flemish Science Foundation (FWO-Vl) and the Methusalem foundation of the Flemish government. Computational resources were provided by the TUBITAK ULAKBIM, High Performance and Grid Computing Center (TRGrid e-Infrastructure), and HPC infrastructure of the University of Antwerp (CalcUA) a division of the Flemish Supercomputer Center (VSC), which is funded by the Hercules foundation. We acknowledge the support from the TUBITAK (Grant No. 115F024 and 116F080). Part of this work was supported by the BAGEP Award of the Science Academy. ; |
Approved |
Most recent IF: 8.867 |
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Call Number |
UA @ lucian @ c:irua:149265UA @ admin @ c:irua:149265 |
Serial |
4945 |
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Author |
Demiroglu, I.; Peeters, F.M.; Gulseren, O.; Cakir, D.; Sevik, C. |
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Title |
Alkali metal intercalation in MXene/graphene heterostructures : a new platform for ion battery applications |
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A1 Journal article |
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Year |
2019 |
Publication |
The journal of physical chemistry letters |
Abbreviated Journal |
J Phys Chem Lett |
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Volume |
10 |
Issue |
4 |
Pages |
727-734 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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Abstract |
The adsorption and diffusion of Na, K, and Ca atoms on MXene/graphene heterostructures of MXene systems Sc2C(OH)(2), Ti2CO2, and V2CO2 are systematically investigated by using first-principles methods. We found that alkali metal intercalation is energetically favorable and thermally stable for Ti2CO2/graphene and V2CO2/graphene heterostructures but not for Sc2C(OH)(2). Diffusion kinetics calculations showed the advantage of MXene/graphene heterostructures over sole MXene systems as the energy barriers are halved for the considered alkali metals. Low energy barriers are found for Na and K ions, which are promising for fast charge/discharge rates. Calculated voltage profiles reveal that estimated high capacities can be fully achieved for Na ion in V2CO2/graphene and Ti2CO2/graphene heterostructures. Our results indicate that Ti2CO2/graphene and V2CO2/graphene electrode materials are very promising for Na ion battery applications. The former could be exploited for low voltage applications while the latter will be more appropriate for higher voltages. |
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000459948800005 |
Publication Date |
2019-01-30 |
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ISSN |
1948-7185 |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
9.353 |
Times cited |
88 |
Open Access |
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Notes |
; We acknowledge the support from the TUBITAK (116F080) and the BAGEP Award of the Science Academy. Part of this work was supported by the FLAG -ERA project TRANS-2D-TMD. A part of this work was supported by University of North Dakota Early Career Award (Grant number: 20622-4000-02624). We also acknowledge financial support from ND EPSCoR through NSF grant OIA-1355466. Computational resources were provided by the High Performance and Grid Computing Center (TRGrid e-Infrastructure) of TUBITAK ULAKBIM, the National Center for High Performance Computing (UHeM) of Istanbul Technical University, and Computational Research Center (HPC Linux cluster) at the University of North Dakota. This work was performed, in part, at the Center for Nanoscale Materials, a U.S. Department of Energy Office of Science User Facility, and supported by the U.S. Department of Energy, Office of Science, under contract no. DE-AC02-06CH11357. ; |
Approved |
Most recent IF: 9.353 |
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Call Number |
UA @ admin @ c:irua:158618 |
Serial |
5194 |
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Author |
Torun, E.; Paleari, F.; Milošević, M.V.; Wirtz, L.; Sevik, C. |
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Title |
Intrinsic control of interlayer exciton generation in Van der Waals materials via Janus layers |
Type |
A1 Journal article |
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Year |
2023 |
Publication |
Nano letters |
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Volume |
23 |
Issue |
8 |
Pages |
3159-3166 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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Abstract |
We demonstrate the possibility of engineering the optical properties of transition metal dichalcogenide heterobilayers when one of the constitutive layers has a Janus structure. We investigate different MoS2@Janus layer combinations using first-principles methods including excitons and exciton-phonon coupling. The direction of the intrinsic electric field from the Janus layer modifies the electronic band alignments and, consequently, the energy separation between dark interlayer exciton states and bright in-plane excitons. We find that in-plane lattice vibrations strongly couple the two states, so that exciton-phonon scattering may be a viable generation mechanism for interlayer excitons upon light absorption. In particular, in the case of MoS2@WSSe, the energy separation of the low-lying interlayer exciton from the in-plane exciton is resonant with the transverse optical phonon modes (40 meV). We thus identify this heterobilayer as a prime candidate for efficient generation of charge-separated electron-hole pairs. |
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000969732100001 |
Publication Date |
2023-04-10 |
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ISSN |
1530-6984 |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
10.8 |
Times cited |
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Open Access |
OpenAccess |
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Approved |
Most recent IF: 10.8; 2023 IF: 12.712 |
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Call Number |
UA @ admin @ c:irua:196034 |
Serial |
8118 |
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