| Records |
| Author |
Kahraman, Z.; Kandemir, A.; Yagmurcukardes, M.; Sahin, H. |
| Title |
Single-layer Janus-type platinum dichalcogenides and their heterostructures |
Type |
A1 Journal article |
| Year |
2019 |
Publication |
The journal of physical chemistry: C : nanomaterials and interfaces |
Abbreviated Journal |
J Phys Chem C |
| Volume |
123 |
Issue |
7 |
Pages |
4549-4557 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
| Abstract |
Ultrathin two-dimensional Janus-type platinum dichalcogenide crystals formed by two different atoms at opposite surfaces are investigated by performing state-of-the-art density functional theory calculations. First, it is shown that single-layer PtX2 structures (where X = S, Se, or Te) crystallize into the dynamically stable IT phase and are indirect band gap semiconductors. It is also found that the substitutional chalcogen doping in all PtX2 structures is favorable via replacement of surface atoms with a smaller chalcogen atom, and such a process leads to the formation of Janus-type platinum dichalcogenides (XPtY, where X and Y stand for S, Se, or Te) which are novel single-layer crystals. While all Janus structures are indirect band gap semiconductors as their binary analogues, their Raman spectra show distinctive features that stem from the broken out-of-plane symmetry. In addition, it is revealed that the construction of Janus crystals enhances the piezoelectric constants of PtX2 crystals significantly both in the in plane and in the out-of-plane directions. Moreover, it is shown that vertically stacked van der Waals heterostructures of binary and ternary (Janus) platinum dichalcogenides offer a wide range of electronic features by forming bilayer heterojunctions of type-I, type-II, and type-III, respectively. Our findings reveal that Janus-type ultrathin platinum dichalcogenide crystals are quite promising materials for optoelectronic device applications. |
| 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 |
|
| Language |
|
Wos |
000459836900071 |
Publication Date |
2019-01-24 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
ISSN  |
1932-7447; 1932-7455 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
4.536 |
Times cited |
20 |
Open Access |
|
| Notes |
; Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure). H.S. and Z.K. acknowledge financial support from the TUBITAK under the project number 117F095. This work is supported by the Flemish Science Foundation (FWO-Vl) by a post-doctoral fellowship (M.Y.). H.S. acknowledges support from Turkiye Bilimler Akademisi-Turkish Academy of Sciences under the GEBIP program. ; |
Approved |
Most recent IF: 4.536 |
| Call Number |
UA @ admin @ c:irua:158617 |
Serial |
5229 |
| Permanent link to this record |
| |
|
| |
| Author |
Eren, I.; Ozen, S.; Sozen, Y.; Yagmurcukardes, M.; Sahin, H. |
| Title |
Vertical van der Waals heterostructure of single layer InSe and SiGe |
Type |
A1 Journal article |
| Year |
2019 |
Publication |
The journal of physical chemistry: C : nanomaterials and interfaces |
Abbreviated Journal |
J Phys Chem C |
| Volume |
123 |
Issue |
51 |
Pages |
31232-31237 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
| Abstract |
We present a first-principles investigation on the stability, electronic structure, and mechanical response of ultrathin heterostructures composed of single layers of InSe and SiGe. First, by performing total energy optimization and phonon calculations, we show that single layers of InSe and SiGe can form dynamically stable heterostructures in 12 different stacking types. Valence and conduction band edges of the heterobilayers form a type-I heterojunction having a tiny band gap ranging between 0.09 and 0.48 eV. Calculations on elastic-stiffness tensor reveal that two mechanically soft single layers form a heterostructure which is stiffer than the constituent layers because of relatively strong interlayer interaction. Moreover, phonon analysis shows that the bilayer heterostructure has highly Raman active modes at 205.3 and 43.7 cm(-1), stemming from the out-of-plane interlayer mode and layer breathing mode, respectively. Our results show that, as a stable type-I heterojunction, ultrathin heterobilayer of InSe/SiGe holds promise for nanoscale device applications. |
| 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 |
|
Wos |
000505632900050 |
Publication Date |
2019-12-03 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1932-7447; 1932-7455 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
4.536 |
Times cited |
|
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 4.536 |
| Call Number |
UA @ admin @ c:irua:165718 |
Serial |
6332 |
| Permanent link to this record |
| |
|
| |
| Author |
Akbali, B.; Yagmurcukardes, M.; Peeters, F.M.; Lin, H.-Y.; Lin, T.-Y.; Chen, W.-H.; Maher, S.; Chen, T.-Y.; Huang, C.-H. |
| Title |
Determining the molecular orientation on the metal nanoparticle surface through surface-enhanced Raman spectroscopy and density functional theory simulations |
Type |
A1 Journal article |
| Year |
2021 |
Publication |
Journal Of Physical Chemistry C |
Abbreviated Journal |
J Phys Chem C |
| Volume |
125 |
Issue |
29 |
Pages |
16289-16295 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
| Abstract |
We report here the efficacy of surface-enhanced Raman spectroscopy (SERS) measurements as a probe for molecular orientation. 4-Aminobenzoic acid (PABA) on a surface consisting of silver (Ag) nanoparticles (NPs) is investigated. We find that the orientation of the PABA molecule on the SERS substrate is estimated based on the relative change in the magnitude of the C-H stretching bands on the SERS substrate, and it is found that the molecule assumes a horizontal orientation on the Ag-NP surface. The strong molecule-metal interaction is determined by an abnormal enhanced SERS band appearing at 980 cm(-1), and the peak is assigned to an out-of-plane amine vibrational mode, which is supported by our ab initio calculations. DFT-based Raman activity calculations corroborate the SERS results, revealing that (i) the PABA molecule attaches to the surface of Ag-NPs with its alpha dimers rather than single-molecule binding and (ii) the molecule preserves its alpha dimers in an aqueous environment. Our results demonstrate that SERS can be used to gain deeper insights into the molecular orientation on metal nanoparticle surfaces. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000680445800055 |
Publication Date |
2021-07-19 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1932-7447; 1932-7455 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
4.536 |
Times cited |
9 |
Open Access |
Not_Open_Access |
| Notes |
|
Approved |
Most recent IF: 4.536 |
| Call Number |
UA @ admin @ c:irua:180455 |
Serial |
6978 |
| Permanent link to this record |
| |
|
| |
| Author |
Yagmurcukardes, M.; Sozen, Y.; Baskurt, M.; Peeters, F.M.; Sahin, H. |
| Title |
Interface-dependent phononic and optical properties of GeO/MoSO heterostructures |
Type |
A1 Journal article |
| Year |
2021 |
Publication |
Nanoscale |
Abbreviated Journal |
Nanoscale |
| Volume |
|
Issue |
|
Pages |
|
| Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
| Abstract |
The interface-dependent electronic, vibrational, piezoelectric, and optical properties of van der Waals heterobilayers, formed by buckled GeO (b-GeO) and Janus MoSO structures, are investigated by means of first-principles calculations. The electronic band dispersions show that O/Ge and S/O interface formations result in a type-II band alignment with direct and indirect band gaps, respectively. In contrast, O/O and S/Ge interfaces give rise to the formation of a type-I band alignment with an indirect band gap. By considering the Bethe-Salpeter equation (BSE) on top of G(0)W(0) approximation, it is shown that different interfaces can be distinguished from each other by means of the optical absorption spectra as a consequence of the band alignments. Additionally, the low- and high-frequency regimes of the Raman spectra are also different for each interface type. The alignment of the individual dipoles, which is interface-dependent, either weakens or strengthens the net dipole of the heterobilayers and results in tunable piezoelectric coefficients. The results indicate that the possible heterobilayers of b-GeO/MoSO asymmetric structures possess various electronic, optical, and piezoelectric properties arising from the different interface formations and can be distinguished by means of various spectroscopic techniques. |
| 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 |
|
Wos |
000738899600001 |
Publication Date |
2021-12-09 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2040-3364 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
7.367 |
Times cited |
5 |
Open Access |
Not_Open_Access |
| Notes |
|
Approved |
Most recent IF: 7.367 |
| Call Number |
UA @ admin @ c:irua:184722 |
Serial |
6998 |
| Permanent link to this record |
| |
|
| |
| Author |
Sun, P.Z.; Yagmurcukardes, M.; Zhang, R.; Kuang, W.J.; Lozada-Hidalgo, M.; Liu, B.L.; Cheng, H.-M.; Wang, F.C.; Peeters, F.M.; Grigorieva, I.V.; Geim, A.K. |
| Title |
Exponentially selective molecular sieving through angstrom pores |
Type |
A1 Journal article |
| Year |
2021 |
Publication |
Nature Communications |
Abbreviated Journal |
Nat Commun |
| Volume |
12 |
Issue |
1 |
Pages |
7170 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
| Abstract |
Two-dimensional crystals with angstrom-scale pores are widely considered as candidates for a next generation of molecular separation technologies aiming to provide extreme, exponentially large selectivity combined with high flow rates. No such pores have been demonstrated experimentally. Here we study gas transport through individual graphene pores created by low intensity exposure to low kV electrons. Helium and hydrogen permeate easily through these pores whereas larger species such as xenon and methane are practically blocked. Permeating gases experience activation barriers that increase quadratically with molecules' kinetic diameter, and the effective diameter of the created pores is estimated as similar to 2 angstroms, about one missing carbon ring. Our work reveals stringent conditions for achieving the long sought-after exponential selectivity using porous two-dimensional membranes and suggests limits on their possible performance. Two-dimensional membranes with angstrom-sized pores are predicted to combine high permeability with exceptional selectivity, but experimental demonstration has been challenging. Here the authors realize angstrom-sized pores in monolayer graphene and demonstrate gas transport with activation barriers increasing quadratically with the molecular kinetic diameter. |
| 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 |
|
Wos |
000728562700016 |
Publication Date |
2021-12-09 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2041-1723 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
12.124 |
Times cited |
28 |
Open Access |
OpenAccess |
| Notes |
|
Approved |
Most recent IF: 12.124 |
| Call Number |
UA @ admin @ c:irua:184840 |
Serial |
6989 |
| Permanent link to this record |
| |
|
| |
| Author |
Cai, J.; Griffin, E.; Guarochico-Moreira, V.H.; Barry, D.; Xin, B.; Yagmurcukardes, M.; Zhang, S.; Geim, A.K.; Peeters, F.M.; Lozada-Hidalgo, M. |
| Title |
Wien effect in interfacial water dissociation through proton-permeable graphene electrodes |
Type |
A1 Journal article |
| Year |
2022 |
Publication |
Nature communications |
Abbreviated Journal |
Nat Commun |
| Volume |
13 |
Issue |
1 |
Pages |
5776-5777 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
| Abstract |
Strong electric fields can accelerate molecular dissociation reactions. The phenomenon known as the Wien effect was previously observed using high-voltage electrolysis cells that produced fields of about 10(7) V m(-1), sufficient to accelerate the dissociation of weakly bound molecules (e.g., organics and weak electrolytes). The observation of the Wien effect for the common case of water dissociation (H2O reversible arrow H+ + OH-) has remained elusive. Here we study the dissociation of interfacial water adjacent to proton-permeable graphene electrodes and observe strong acceleration of the reaction in fields reaching above 10(8) V m(-1). The use of graphene electrodes allows measuring the proton currents arising exclusively from the dissociation of interfacial water, while the electric field driving the reaction is monitored through the carrier density induced in graphene by the same field. The observed exponential increase in proton currents is in quantitative agreement with Onsager's theory. Our results also demonstrate that graphene electrodes can be valuable for the investigation of various interfacial phenomena involving proton transport. |
| 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 |
|
Wos |
000862552600012 |
Publication Date |
2022-10-01 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2041-1723 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
16.6 |
Times cited |
14 |
Open Access |
OpenAccess |
| Notes |
|
Approved |
Most recent IF: 16.6 |
| Call Number |
UA @ admin @ c:irua:191575 |
Serial |
7228 |
| Permanent link to this record |
| |
|
| |
| Author |
Zhou, Z.; Tan, Y.; Yang, Q.; Bera, A.; Xiong, Z.; Yagmurcukardes, M.; Kim, M.; Zou, Y.; Wang, G.; Mishchenko, A.; Timokhin, I.; Wang, C.; Wang, H.; Yang, C.; Lu, Y.; Boya, R.; Liao, H.; Haigh, S.; Liu, H.; Peeters, F.M.; Li, Y.; Geim, A.K.; Hu, S. |
| Title |
Gas permeation through graphdiyne-based nanoporous membranes |
Type |
A1 Journal article |
| Year |
2022 |
Publication |
Nature communications |
Abbreviated Journal |
Nat Commun |
| Volume |
13 |
Issue |
1 |
Pages |
4031-4036 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
| Abstract |
Nanoporous membranes based on two dimensional materials are predicted to provide highly selective gas transport in combination with extreme permeance. Here we investigate membranes made from multilayer graphdiyne, a graphene-like crystal with a larger unit cell. Despite being nearly a hundred of nanometers thick, the membranes allow fast, Knudsen-type permeation of light gases such as helium and hydrogen whereas heavy noble gases like xenon exhibit strongly suppressed flows. Using isotope and cryogenic temperature measurements, the seemingly conflicting characteristics are explained by a high density of straight-through holes (direct porosity of similar to 0.1%), in which heavy atoms are adsorbed on the walls, partially blocking Knudsen flows. Our work offers important insights into intricate transport mechanisms playing a role at nanoscale. |
| 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 |
000918423100001 |
Publication Date |
2022-07-12 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2041-1723 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
16.6 |
Times cited |
21 |
Open Access |
OpenAccess |
| Notes |
|
Approved |
Most recent IF: 16.6 |
| Call Number |
UA @ admin @ c:irua:194402 |
Serial |
7308 |
| Permanent link to this record |
| |
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| |
| Author |
Iyikanat, F.; Yagmurcukardes, M.; Senger, R.T.; Sahin, H. |
| Title |
Tuning electronic and magnetic properties of monolayer \alpha-RuCl3 by in-plane strain |
Type |
A1 Journal article |
| Year |
2018 |
Publication |
Journal of materials chemistry C : materials for optical and electronic devices |
Abbreviated Journal |
J Mater Chem C |
| Volume |
6 |
Issue |
8 |
Pages |
2019-2025 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
By employing density functional theory-based methods, the structural, vibrational, electronic, and magnetic properties of monolayer -RuCl3 were investigated. It was demonstrated that ferromagnetic (FM) and zigzag-antiferromagnetic (ZZ-AFM) spin orders in the material have very close total energies with the latter being the ground state. We found that each Ru atom possesses a magnetic moment of 0.9 (B) and the material exhibits strong magnetic anisotropy. While both phases exhibit indirect gaps, the FM phase is a magnetic semiconductor and the ZZ-AFM phase is a non-magnetic semiconductor. The structural stability of the material was confirmed by phonon calculations. Moreover, dynamical analysis revealed that the magnetic order in the material can be monitored via Raman measurements of the crystal structure. In addition, the magnetic ground state of the material changes from ZZ-AFM to FM upon certain applied strains. Valence and conduction band-edges of the material vary considerably under in-plane strains. Owing to the stable lattice structure and unique and controllable magnetic properties, monolayer -RuCl3 is a promising material in nanoscale device applications. |
| 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 |
|
Wos |
000426483800015 |
Publication Date |
2018-01-22 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2050-7526; 2050-7534 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
5.256 |
Times cited |
16 |
Open Access |
|
| Notes |
; Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure). H. S. acknowledges financial support from TUBITAK under project number 116C073. H. S. also acknowledges support from Bilim Akademisi-The Science Academy, Turkey, under the BAGEP program. ; |
Approved |
Most recent IF: 5.256 |
| Call Number |
UA @ lucian @ c:irua:149900UA @ admin @ c:irua:149900 |
Serial |
4952 |
| Permanent link to this record |
| |
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| |
| Author |
Bacaksiz, C.; Yagmurcukardes, M.; Peeters, F.M.; Milošević, M.V. |
| Title |
Hematite at its thinnest limit |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
2d Materials |
Abbreviated Journal |
2D Mater |
| Volume |
7 |
Issue |
2 |
Pages |
025029 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Motivated by the recent synthesis of two-dimensional alpha-Fe2O3 (Balan et al 2018 Nat. Nanotechnol. 13 602), we analyze the structural, vibrational, electronic and magnetic properties of single- and few-layer alpha-Fe2O3 compared to bulk, by ab initio and Monte-Carlo simulations. We reveal how monolayer alpha-Fe2O3 (hematene) can be distinguished from the few-layer structures, and how they all differ from bulk through observable Raman spectra. The optical spectra exhibit gradual shift of the prominent peak to higher energy, as well as additional features at lower energy when alpha-Fe2O3 is thinned down to a monolayer. Both optical and electronic properties have strong spin asymmetry, meaning that lower-energy optical and electronic activities are allowed for the single-spin state. Finally, our considerations of magnetic properties reveal that 2D hematite has anti-ferromagnetic ground state for all thicknesses, but the critical temperature for Morin transition increases with decreasing sample thickness. On all accounts, the link to available experimental data is made, and further measurements are prompted. |
| 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 |
000537341000002 |
Publication Date |
2020-01-20 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2053-1583 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
5.5 |
Times cited |
12 |
Open Access |
|
| Notes |
; This work was supported by Research Foundation-Flanders (FWO-Vlaanderen). Computational resources were provided by Flemish Supercomputer Center(VSC), and TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure). Part of this work was also supported by FLAG-ERA project TRANS-2D-TMD and TOPBOF-UAntwerp. MY was supported by a postdoctoral fellowship from the Flemish Science Foundation (FWO-Vl). ; |
Approved |
Most recent IF: 5.5; 2020 IF: 6.937 |
| Call Number |
UA @ admin @ c:irua:170301 |
Serial |
6533 |
| Permanent link to this record |
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| |
| Author |
Yagmurcukardes, M.; Senger, R.T.; Peeters, F.M.; Sahin, H. |
| Title |
Mechanical properties of monolayer GaS and GaSe crystals |
Type |
A1 Journal article |
| Year |
2016 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
| Volume |
94 |
Issue |
94 |
Pages |
245407 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
The mechanical properties of monolayer GaS and GaSe crystals are investigated in terms of their elastic constants: in-plane stiffness (C), Poisson ratio (nu), and ultimate strength (sigma(U)) by means of first-principles calculations. The calculated elastic constants are compared with those of graphene and monolayer MoS2. Our results indicate that monolayer GaS is a stiffer material than monolayer GaSe crystals due to the more ionic character of the Ga-S bonds than the Ga-Se bonds. Although their Poisson ratio values are very close to each other, 0.26 and 0.25 for GaS and GaSe, respectively, monolayer GaS is a stronger material than monolayer GaSe due to its slightly higher sU value. However, GaS and GaSe crystals are found to be more ductile and flexible materials than graphene and MoS2. We have also analyzed the band-gap response of GaS and GaSe monolayers to biaxial tensile strain and predicted a semiconductor-metal crossover after 17% and 14% applied strain, respectively, for monolayer GaS and GaSe. In addition, we investigated how the mechanical properties are affected by charging. We found that the flexibility of single layer GaS and GaSe displays a sharp increase under 0.1e/cell charging due to the repulsive interactions between extra charges located on chalcogen atoms. These charging-controllable mechanical properties of single layers of GaS and GaSe can be of potential use for electromechanical applications. |
| 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 |
000389503400008 |
Publication Date |
2016-12-05 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2469-9950;2469-9969; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
108 |
Open Access |
|
| Notes |
; Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure). H.S. acknowledges support from Bilim Akademisi-The Science Academy, Turkey under the BAGEP program. R.T.S. acknowledges the support from TUBITAK through project 114F397. ; |
Approved |
Most recent IF: 3.836 |
| Call Number |
UA @ lucian @ c:irua:139229 |
Serial |
4356 |
| Permanent link to this record |
| |
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| |
| Author |
Yagmurcukardes, M.; Torun, E.; Senger, R.T.; Peeters, F.M.; Sahin, H. |
| Title |
Mg(OH)2-WS2 van der Waals heterobilayer : electric field tunable band-gap crossover |
Type |
A1 Journal article |
| Year |
2016 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
| Volume |
94 |
Issue |
94 |
Pages |
195403 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Magnesium hydroxide [Mg(OH)(2)] has a layered brucitelike structure in its bulk form and was recently isolated as a new member of two-dimensional monolayer materials. We investigated the electronic and optical properties of monolayer crystals of Mg(OH)(2) and WS2 and their possible heterobilayer structure by means of first-principles calculations. It was found that both monolayers of Mg(OH)(2) and WS2 are direct-gap semiconductors and these two monolayers form a typical van der Waals heterostructure with a weak interlayer interaction and a type-II band alignment with a staggered gap that spatially separates electrons and holes. We also showed that an out-of-plane electric field induces a transition from a staggered to a straddling-type heterojunction. Moreover, by solving the Bethe-Salpeter equation on top of single-shot G(0)W(0) calculations, we show that the low-energy spectrum of the heterobilayer is dominated by the intralyer excitons of the WS2 monolayer. Because of the staggered interfacial gap and the field-tunable energy-band structure, the Mg(OH)(2)-WS2 heterobilayer can become an important candidate for various optoelectronic device applications in nanoscale. |
| 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 |
|
Wos |
000386769400007 |
Publication Date |
2016-11-03 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2469-9950;2469-9969; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
38 |
Open Access |
|
| 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). H.S. is supported by a FWOPegasus Long Marie Curie Fellowship. H.S. and R.T.S. acknowledge support from TUBITAK through Project No. 114F397. H.S. acknowledges support from Bilim Akademisi – The Science Academy, Turkey, under the BAGEP program. ; |
Approved |
Most recent IF: 3.836 |
| Call Number |
UA @ lucian @ c:irua:138205 |
Serial |
4364 |
| Permanent link to this record |
| |
|
| |
| Author |
Yagmurcukardes, M.; Bacaksiz, C.; Unsal, E.; Akbali, B.; Senger, R.T.; Sahin, H. |
| Title |
Strain mapping in single-layer two-dimensional crystals via Raman activity |
Type |
A1 Journal article |
| Year |
2018 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
| Volume |
97 |
Issue |
11 |
Pages |
115427 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
By performing density functional theory-based ab initio calculations, Raman-active phonon modes of single-layer two-dimensional (2D) materials and the effect of in-plane biaxial strain on the peak frequencies and corresponding activities of the Raman-active modes are calculated. Our findings confirm the Raman spectrum of the unstrained 2D crystals and provide expected variations in the Raman-active modes of the crystals under in-plane biaxial strain. The results are summarized as follows: (i) frequencies of the phonon modes soften (harden) under applied tensile (compressive) strains; (ii) the response of the Raman activities to applied strain for the in-plane and out-of-plane vibrational modes have opposite trends, thus, the built-in strains in the materials can be monitored by tracking the relative activities of those modes; (iii) in particular, the A peak in single-layer Si and Ge disappears under a critical tensile strain; (iv) especially in mono-and diatomic single layers, the shift of the peak frequencies is a stronger indication of the strain rather than the change in Raman activities; (v) Raman-active modes of single-layer ReX2 (X = S, Se) are almost irresponsive to the applied strain. Strain-induced modifications in the Raman spectrum of 2D materials in terms of the peak positions and the relative Raman activities of the modes could be a convenient tool for characterization. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
American Physical Society |
Place of Publication |
New York, N.Y |
Editor |
|
| Language |
|
Wos |
000427799300006 |
Publication Date |
2018-03-19 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
21 |
Open Access |
|
| Notes |
; Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure). H.S. acknowledges financial support from the Scientific and Technological Research Council of Turkey (TUBITAK) under Project No. 116C073. ; |
Approved |
Most recent IF: 3.836 |
| Call Number |
UA @ lucian @ c:irua:150840UA @ admin @ c:irua:150840 |
Serial |
4979 |
| Permanent link to this record |
| |
|
| |
| Author |
Yagmurcukardes, M.; Peeters, F.M.; Sahin, H. |
| Title |
Electronic and vibrational properties of PbI2: From bulk to monolayer |
Type |
A1 Journal article |
| Year |
2018 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
| Volume |
98 |
Issue |
8 |
Pages |
085431 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Using first-principles calculations, we study the dependence of the electronic and vibrational properties of multilayered PbI2 crystals on the number of layers and focus on the electronic-band structure and the Raman spectrum. Electronic-band structure calculations reveal that the direct or indirect semiconducting behavior of PbI2 is strongly influenced by the number of layers. We find that at 3L thickness there is a direct-to-indirect band gap transition (from bulk-to-monolayer). It is shown that in the Raman spectrum two prominent peaks, A(1g) and E-g, exhibit phonon hardening with an increasing number of layers due to the interlayer van der Waals interaction. Moreover, the Raman activity of the A(1g) mode significantly increases with an increasing number of layers due to the enhanced out-of-plane dielectric constant in the few-layer case. We further characterize rigid-layer vibrations of low-frequency interlayer shear (C) and breathing (LB) modes in few-layer PbI2. A reduced monatomic (linear) chain model (LCM) provides a fairly accurate picture of the number of layers dependence of the low-frequency modes and it is shown also to be a powerful tool to study the interlayer coupling strength in layered PbI2. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
American Physical Society |
Place of Publication |
New York, N.Y |
Editor |
|
| Language |
|
Wos |
000442667200008 |
Publication Date |
2018-08-24 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
41 |
Open Access |
|
| Notes |
; Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure). H.S. acknowledges financial support from the Scientific and Technological Research Council of Turkey (TUBITAK) under Project No. 117F095. Part of this work was supported by FLAG-ERA project TRANS-2D-TMD. ; |
Approved |
Most recent IF: 3.836 |
| Call Number |
UA @ lucian @ c:irua:153716UA @ admin @ c:irua:153716 |
Serial |
5097 |
| Permanent link to this record |
| |
|
| |
| Author |
Yagmurcukardes, M.; Ozen, S.; Iyikanat, F.; Peeters, F.M.; Sahin, H. |
| Title |
Raman fingerprint of stacking order in HfS2-Ca(OH)(2) heterobilayer |
Type |
A1 Journal article |
| Year |
2019 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
| Volume |
99 |
Issue |
20 |
Pages |
205405 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Using density functional theory-based first-principles calculations, we investigate the stacking order dependence of the electronic and vibrational properties of HfS2-Ca(OH)(2) heterobilayer structures. It is shown that while the different stacking types exhibit similar electronic and optical properties, they are distinguishable from each other in terms of their vibrational properties. Our findings on the vibrational properties are the following: (i) from the interlayer shear (SM) and layer breathing (LBM) modes we are able to deduce the AB' stacking order, (ii) in addition, the AB' stacking type can also be identified via the phonon softening of E-g(I) and A(g)(III) modes which harden in the other two stacking types, and (iii) importantly, the ultrahigh frequency regime possesses distinctive properties from which we can distinguish between all stacking types. Moreover, the differences in optical and vibrational properties of various stacking types are driven by two physical effects, induced biaxial strain on the layers and the layer-layer interaction. Our results reveal that with both the phonon frequencies and corresponding activities, the Raman spectrum possesses distinctive properties for monitoring the stacking type in novel vertical heterostructures constructed by alkaline-earth-metal hydroxides. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000467387800010 |
Publication Date |
2019-05-06 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
27 |
Open Access |
|
| Notes |
; Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure). H.S. acknowledges financial support from the Scientific and Technological Research Council of Turkey (TUBITAK) under the Project No. 117F095. H.S. acknowledges support from Turkish Academy of Sciences under the GEBIP program. This work is supported by the Flemish Science Foundation (FWO-Vl) by a postdoctoral fellowship (M.Y.). ; |
Approved |
Most recent IF: 3.836 |
| Call Number |
UA @ admin @ c:irua:160334 |
Serial |
5226 |
| Permanent link to this record |
| |
|
| |
| Author |
Yagmurcukardes, M.; Sevik, C.; Peeters, F.M. |
| Title |
Electronic, vibrational, elastic, and piezoelectric properties of monolayer Janus MoSTe phases: A first-principles study |
Type |
A1 Journal article |
| Year |
2019 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
| Volume |
100 |
Issue |
4 |
Pages |
045415 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| 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. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000476687800003 |
Publication Date |
2019-07-19 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
128 |
Open Access |
|
| 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 |
| Call Number |
UA @ admin @ c:irua:161899 |
Serial |
5411 |
| Permanent link to this record |
| |
|
| |
| Author |
Yagmurcukardes, M. |
| Title |
Monolayer fluoro-InSe : formation of a thin monolayer via fluorination of InSe |
Type |
A1 Journal article |
| Year |
2019 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
| Volume |
100 |
Issue |
2 |
Pages |
024108 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
By performing density functional theory-based first-principles calculations, the formation of a thin monolayer structure, namely InSeF, via fluorination of monolayer InSe is predicted. It is shown that strong interaction of F and In atoms leads to the detachment of In-Se layers in monolayer InSe and 1T-like monolayer InSeF structure is formed. Monolayer InSeF is found to be dynamically stable in terms of its phonon band dispersions. In addition, its Raman spectrum is shown to exhibit totally distinctive features as compared to monolayer InSe. The electronic band dispersions reveal that monolayer InSeF is a direct gap semiconductor whose valence and conduction band edges reside at the Gamma point. Moreover, the orientation-dependent linear elastic properties of monolayer InSeF are investigated in terms of the in-plane stiffness and Poisson ratio. It is found that monolayer InSeF displays strong in-plane anisotropy in elastic constants and it is slightly softer material as compared to monolayer InSe. Overall, it is proposed that a thin, direct gap semiconducting monolayer InSeF can be formed by full fluorination of monolayer InSe as a new member of the two-dimensional family. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000477885700003 |
Publication Date |
2019-07-29 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
9 |
Open Access |
|
| Notes |
; Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure). This work is supported by the Flemish Science Foundation (FWO-Vl) by a postdoctoral fellowship (M.Y.). ; |
Approved |
Most recent IF: 3.836 |
| Call Number |
UA @ admin @ c:irua:161891 |
Serial |
5423 |
| Permanent link to this record |
| |
|
| |
| Author |
Li, L.L.; Bacaksiz, C.; Nakhaee, M.; Pentcheva, R.; Peeters, F.M.; Yagmurcukardes, M. |
| Title |
Single-layer Janus black arsenic-phosphorus (b-AsP): optical dichroism, anisotropic vibrational, thermal, and elastic properties |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
| Volume |
101 |
Issue |
13 |
Pages |
134102-134109 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
By using density functional theory (DFT) calculations, we predict a puckered, dynamically stable Janus single-layer black arsenic-phosphorus (b-AsP), which is composed of two different atomic sublayers, arsenic and phosphorus atoms. The calculated phonon spectrum reveals that Janus single-layer b-AsP is dynamically stable with either pure or coupled optical phonon branches arising from As and P atoms. The calculated Raman spectrum indicates that due to the relatively strong P-P bonds, As atoms have no contribution to the highfrequency optical vibrations. In addition, the orientation-dependent isovolume heat capacity reveals anisotropic contributions of LA and TA phonon branches to the low-temperature thermal properties. Unlike pristine single layers of b-As and b-P, Janus single-layer b-AsP exhibits additional out-of-plane asymmetry which leads to important consequences for its electronic, optical, and elastic properties. In contrast to single-layer b-As, Janus single-layer b-AsP is found to possess a direct band gap dominated by the P atoms. Moreover, real and imaginary parts of the dynamical dielectric function, including excitonic effects, reveal the highly anisotropic optical feature of the Janus single-layer. A tight-binding (TB) model is also presented for Janus single-layer b-AsP, and it is shown that, with up to seven nearest hoppings, the TB model reproduces well the DFT band structure in the low-energy region around the band gap. This TB model can be used in combination with the Green's function approach to study, e.g., quantum transport in finite systems based on Janus single-layer b-AsP. Furthermore, the linear-elastic properties of Janus single-layer b-AsP are investigated, and the orientation-dependent in-plane stiffness and Poisson ratio are calculated. It is found that the Janus single layer exhibits strong in-plane anisotropy in its Poisson ratio much larger than that of single-layer b-P. This Janus single layer is relevant for promising applications in optical dichroism and anisotropic nanoelasticity. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000524531900001 |
Publication Date |
2020-04-09 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.7 |
Times cited |
39 |
Open Access |
|
| Notes |
; This work was supported by the German Science Foundation (DFG) within SFB/TRR80 (project G3) and the FLAGERA project TRANS-2D-TMD. M.Y. was supported by a postdoctoral fellowship from the Flemish Science Foundation (FWO-Vl). Computational resources were provided by the Flemish Supercomputer Center (VSC) and Leibniz Supercomputer Centrum (project pr87ro). ; |
Approved |
Most recent IF: 3.7; 2020 IF: 3.836 |
| Call Number |
UA @ admin @ c:irua:168554 |
Serial |
6602 |
| Permanent link to this record |
| |
|
| |
| Author |
Yagmurcukardes, M.; Peeters, F.M. |
| Title |
Stable single layer of Janus MoSO: strong out-of-plane piezoelectricity |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
| Volume |
101 |
Issue |
15 |
Pages |
155205-155208 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Using density functional theory based first-principles calculations, we predict the dynamically stable 1H phase of a Janus single layer composed of S-Mo-O atomic layers. It is an indirect band gap semiconductor exhibiting strong polarization arising from the charge difference on the two surfaces. In contrast to 1H phases of MoS2 and MoO2, Janus MoSO is found to possess four Raman active phonon modes and a large out-of-plane piezoelectric coefficient which is absent in fully symmetric single layers of MoS2 and MoO2. We investigated the electronic and phononic properties under applied biaxial strain and found an electronic phase transition with tensile strain while the conduction band edge displays a shift when under compressive strain. Furthermore, single-layer MoSO exhibits phononic stability up to 5% of compressive and 11% of tensile strain with significant phonon shifts. The phonon instability is shown to arise from the soft in-plane and out-of-plane acoustic modes at finite wave vector. The large strain tolerance of Janus MoSO is important for nanoelastic applications. In view of the dynamical stability even under moderate strain, we expect that Janus MoSO can be fabricated in the common 1H phase with a strong out-of-plane piezoelectric coefficient. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
|
Place of Publication |
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Editor |
|
| Language |
|
Wos |
000528507900003 |
Publication Date |
2020-04-24 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.7 |
Times cited |
66 |
Open Access |
|
| Notes |
; Computational resources were provided by the Flemish Supercomputer Center (VSC). M.Y. is supported by the Flemish Science Foundation (FWO-Vl) through a postdoctoral fellowship. ; |
Approved |
Most recent IF: 3.7; 2020 IF: 3.836 |
| Call Number |
UA @ admin @ c:irua:169566 |
Serial |
6614 |
| Permanent link to this record |
| |
|
| |
| Author |
Ceyhan, E.; Yagmurcukardes, M.; Peeters, F.M.; Sahin, H. |
| Title |
Electronic and magnetic properties of single-layer FeCl₂ with defects |
Type |
A1 Journal article |
| Year |
2021 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
| Volume |
103 |
Issue |
1 |
Pages |
014106 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
The formation of lattice defects and their effect on the electronic properties of single-layer FeCl2 are investigated by means of first-principles calculations. Among the vacancy defects, namely mono-, di-, and three-Cl vacancies and mono-Fe vacancy, the formation of mono-Cl vacancy is the most preferable. Comparison of two different antisite defects reveals that the formation of the Fe-antisite defect is energetically preferable to the Cl-antisite defect. While a single Cl vacancy leads to a 1 mu(B) decrease in the total magnetic moment of the host lattice, each Fe vacant site reduces the magnetic moment by 4 mu(B). However, adsorption of an excess Cl atom on the surface changes the electronic structure to a ferromagnetic metal or to a ferromagnetic semiconductor depending on the adsorption site without changing the ferromagnetic state of the host lattice. Both Cl-antisite and Fe-antisite defected domains change the magnetic moment of the host lattice by -1 mu(B) and +3 mu(B), respectively. The electronic ground state of defected structures reveals that (i) single-layer FeCl2 exhibits half-metallicity under the formation of vacancy and Cl-antisite defects; (ii) ferromagnetic metallicity is obtained when a single Cl atom is adsorbed on upper-Cl and Fe sites, respectively; and (iii) ferromagnetic semiconducting behavior is found when a Cl atom is adsorbed on a lower-Cl site or a Fe-antisite defect is formed. Simulated scanning electron microscope images show that atomic-scale identification of defect types is possible from their electronic charge density. Further investigation of the periodically Fe-defected structures reveals that the formation of the single-layer FeCl3 phase, which is a dynamically stable antiferromagnetic semiconductor, is possible. Our comprehensive analysis on defects in single-layer FeCl2 will complement forthcoming experimental observations. |
| 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 |
000606969400002 |
Publication Date |
2021-01-13 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
7 |
Open Access |
Not_Open_Access |
| Notes |
; Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure), and by Flemish Supercomputer Center (VSC). H.S. acknowledges financial support from the Scientific and Technological Research Council of Turkey (TUBITAK) under Project No. 117F095. M.Y. was supported by the Flemish Science Foundation (FWO-Vl) by a postdoctoral fellowship. ; |
Approved |
Most recent IF: 3.836 |
| Call Number |
UA @ admin @ c:irua:176039 |
Serial |
6689 |
| Permanent link to this record |
| |
|
| |
| Author |
Shekarforoush, S.; Jalali, H.; Yagmurcukardes, M.; Milošević, M.V.; Neek-Amal, M. |
| Title |
Optoelectronic properties of confined water in angstrom-scale slits |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
| Volume |
102 |
Issue |
23 |
Pages |
235406 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
The optoelectronic properties of confined water form one of the most active research areas in the past few years. Here we present the multiscale methodology to discern the out-of-plane electronic and dipolar dielectric constants (epsilon(el)(perpendicular to) and epsilon(diP)(perpendicular to)) of strongly confined water. We reveal that epsilon(perpendicular to el) and epsilon(diP)(perpendicular to) become comparable for water confined in angstrom-scale channels (with a height of less than 15 angstrom) within graphene (GE) and hexagonal boron nitride (hBN) bilayers. Channel height (h) associated with a minimum in both epsilon(e)(l)(perpendicular to) and epsilon(dip)(perpendicular to) is linked to the formation of the ordered structure of ice for h approximate to (7 -7.5) angstrom. The recently measured total dielectric constant epsilon(T)(perpendicular to) of nanoconfined water [L. Fumagalli et al., Science 360, 1339 (2018)] is corroborated by our results. Furthermore, we evaluate the contribution from the encapsulating membranes to the dielectric properties, as a function of the interlayer spacing, i.e., the height of the confining channel for water. Finally, we conduct analysis of the optical properties of both confined water and GE membranes, and show that the electron energy loss function of confined water strongly differs from that of bulk water. |
| 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 |
|
Wos |
000595856100004 |
Publication Date |
2020-12-04 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.7 |
Times cited |
1 |
Open Access |
|
| Notes |
; This work was supported by the Research Foundation – Flanders (FWO). M.Y. gratefully acknowledges his FWO postdoctoral mandate. ; |
Approved |
Most recent IF: 3.7; 2020 IF: 3.836 |
| Call Number |
UA @ admin @ c:irua:175051 |
Serial |
6695 |
| Permanent link to this record |
| |
|
| |
| Author |
Varjovi, M.J.; Yagmurcukardes, M.; Peeters, F.M.; Durgun, E. |
| Title |
Janus two-dimensional transition metal dichalcogenide oxides: First-principles investigation of WXO monolayers with X = S, Se, and Te |
Type |
A1 Journal article |
| Year |
2021 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
| Volume |
103 |
Issue |
19 |
Pages |
195438 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Structural symmetry breaking in two-dimensional materials can lead to superior physical properties and introduce an additional degree of piezoelectricity. In the present paper, we propose three structural phases (1H, 1T, and 1T') of Janus WXO (X = S, Se, and Te) monolayers and investigate their vibrational, thermal, elastic, piezoelectric, and electronic properties by using first-principles methods. Phonon spectra analysis reveals that while the 1H phase is dynamically stable, the 1T phase exhibits imaginary frequencies and transforms to the distorted 1T' phase. Ab initio molecular dynamics simulations confirm that 1H- and 1T'-WXO monolayers are thermally stable even at high temperatures without any significant structural deformations. Different from binary systems, additional Raman active modes appear upon the formation of Janus monolayers. Although the mechanical properties of 1H-WXO are found to be isotropic, they are orientation dependent for 1T'-WXO. It is also shown that 1H-WXO monolayers are indirect band-gap semiconductors and the band gap narrows down the chalcogen group. Except 1T'-WSO, 1T'-WXO monolayers have a narrow band gap correlated with the Peierls distortion. The effect of spin-orbit coupling on the band structure is also examined for both phases and the alteration in the band gap is estimated. The versatile mechanical and electronic properties of Janus WXO monolayers together with their large piezoelectric response imply that these systems are interesting for several nanoelectronic applications. |
| 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 |
000655902600004 |
Publication Date |
2021-05-26 |
| 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 |
| Impact Factor |
3.836 |
Times cited |
78 |
Open Access |
Not_Open_Access |
| Notes |
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Approved |
Most recent IF: 3.836 |
| Call Number |
UA @ admin @ c:irua:179050 |
Serial |
7000 |
| Permanent link to this record |
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| Author |
Yagmurcukardes, M.; Mogulkoc, Y.; Akgenc, B.; Mogulkoc, A.; Peeters, F.M. |
| Title |
Prediction of monoclinic single-layer Janus Ga₂ Te X (X = S and Se) : strong in-plane anisotropy |
Type |
A1 Journal article |
| Year |
2021 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
| Volume |
104 |
Issue |
4 |
Pages |
045425 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
By using density functional theory (DFT) based first-principles calculations, electronic, vibrational, piezo-electric, and optical properties of monoclinic Janus single-layer Ga2TeX (X = S or Se) are investigated. The dynamical, mechanical, and thermal stability of the proposed Janus single layers are verified by means of phonon bands, stiffness tensor, and quantum molecular dynamics simulations. The calculated vibrational spectrum reveals the either pure or coupled optical phonon branches arising from Ga-Te and Ga-X atoms. In addition to the in-plane anisotropy, single-layer Janus Ga2TeX exhibits additional out-of-plane asymmetry, which leads to important consequences for its electronic and optical properties. Electronic band dispersions indicate the direct band-gap semiconducting nature of the constructed Janus structures with energy band gaps falling into visible spectrum. Moreover, while orientation-dependent linear-elastic properties of Janus single layers indicate their strong anisotropy, the calculated in-plane stiffness values reveal the ultrasoft nature of the structures. In addition, predicted piezoelectric coefficients show that while there is a strong in-plane anisotropy between piezoelectric constants along armchair (AC) and zigzag (ZZ) directions, there exists a tiny polarization along the out-of-plane direction as a result of the formation of Janus structure. The optical response to electromagnetic radiation has been also analyzed through density functional theory by considering the independent-particle approximation. Finally, the optical spectra of Janus Ga2TeX structures is investigated and it showed a shift from the ultraviolet region to the visible region. The fact that the spectrum is between these regions will allow it to be used in solar energy and many nanoelectronics applications. The predicted monoclinic single-layer Janus Ga2TeX are relevant for promising applications in optoelectronics, optical dichroism, and anisotropic nanoelasticity. |
| 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 |
000678811100007 |
Publication Date |
2021-07-26 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
14 |
Open Access |
Not_Open_Access |
| Notes |
|
Approved |
Most recent IF: 3.836 |
| Call Number |
UA @ admin @ c:irua:180404 |
Serial |
7013 |
| Permanent link to this record |
