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Records |
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Author |
Shi, W.; Callewaert, V.; Barbiellini, B.; Saniz, R.; Butterling, M.; Egger, W.; Dickmann, M.; Hugenschmidt, C.; Shakeri, B.; Meulenberg, R. W.; Brück, E.; Partoens, B.; Bansil, A.; Eijt, S.W. H. |
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Title |
Nature of the Positron State in CdSe Quantum Dots |
Type |
A1 Journal article |
| |
Year |
2018 |
Publication |
Physical review letters |
Abbreviated Journal |
Phys Rev Lett |
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| |
Volume |
121 |
Issue |
5 |
Pages |
057401 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Previous studies have shown that positron-annihilation spectroscopy is a highly sensitive probe of the electronic structure and surface composition of ligand-capped semiconductor quantum dots (QDs) embedded in thin films. The nature of the associated positron state, however, whether the positron is confined inside the QDs or localized at their surfaces, has so far remained unresolved. Our positron-annihilation lifetime spectroscopy studies of CdSe QDs reveal the presence of a strong lifetime component in the narrow range of 358–371 ps, indicating abundant trapping and annihilation of positrons at the surfaces of the QDs. Furthermore, our ab initio calculations of the positron wave function and lifetime employing a recent formulation of the weighted density approximation demonstrate the presence of a positron surface state and predict positron lifetimes close to experimental values. Our study thus resolves the long-standing question regarding the nature of the positron state in semiconductor QDs and opens the way to extract quantitative information on surface composition and ligand-surface interactions of colloidal semiconductor QDs through highly sensitive positron-annihilation techniques. |
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Wos |
000440635300012 |
Publication Date |
2018-08-02 |
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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 |
0031-9007 |
ISBN |
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Additional Links  |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
8.462 |
Times cited |
6 |
Open Access |
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Notes |
The work at Delft University of Technology was supported by the China Scholarship Council (CSC) grant of W. S. We acknowledge financial support for this research from ADEM, A green Deal in Energy Materials of the Ministry of Economic Affairs of The Netherlands. The PALS study is based upon experiments performed at the PLEPS instrument of the NEPOMUC facility at the Heinz Maier-Leibnitz Zentrum (MLZ), Garching, Germany, and was supported by the European Commission under the 7th Framework Program, Key Action: Strengthening the European Research Area, Research Infrastructures, Contract No. 226507, NMI3. The work at the University of Maine was supported by the National Science Foundation under Grant No. DMR-1206940. V. C. and R. S. were supported by the FWO-Vlaanderen through Project No. G. 0224.14N. Computational resources and services used in this work were in part provided by the VSC (Flemish Supercomputer Center) and the HPC infrastructure of the University of Antwerp (CalcUA), both funded by the FWO-Vlaanderen and the Flemish Government (EWI Department). The work at Northeastern University was supported by the U.S. Department of Energy (DOE), Office of Science, Basic Energy Sciences Grant No. DE-FG02-07ER46352 (core research), and benefited from Northeastern University’s Advanced Scientific Computation Center (ASCC), the National Energy Research Scientific Computing Center (NERSC) through DOE Grant No. DE-AC02-05CH11231, and support (functionals for modeling positron spectros- copies of layered materials) from the DOE EFRC: Center for the Computational Design of Functional Layered Materials (CCDM) under DE-SC0012575. |
Approved |
Most recent IF: 8.462 |
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Call Number |
CMT @ cmt @c:irua:152999UA @ admin @ c:irua:152999 |
Serial |
5009 |
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| Permanent link to this record |
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Author |
Vodolazov, D.Y.; Berdiyorov, G.; Peeters, F.M. |
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Title |
Negative magnetoresistance in thin superconducting films with parallel orientation of current and magnetic field |
Type |
A1 Journal article |
| |
Year |
2018 |
Publication |
Physica: C : superconductivity |
Abbreviated Journal |
Physica C |
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| |
Volume |
552 |
Issue |
552 |
Pages |
64-66 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Thin superconducting films can exhibit negative magnetoresistance when an in-plane external magnetic field is aligned parallel with the transport current. We explain this effect as due to appearance of parallel vortices in the plain of the film at the first critical magnetic field H-c1 which leads to an enhancement of the superconducting properties and impedes the motion of the current induced perpendicular vortices. Our theoretical results are based on a numerical solution of the time-dependent and stationary 3D Ginzburg-Landau equations. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Amsterdam |
Editor |
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Language |
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Wos |
000440786600012 |
Publication Date |
2018-07-20 |
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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 |
0921-4534 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
1.404 |
Times cited |
6 |
Open Access |
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Notes |
; The work is supported by the Russian Science Foundation Project No. 17-72-30036 and the Malthusian programme of the Flemish government. ; |
Approved |
Most recent IF: 1.404 |
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| |
Call Number |
UA @ lucian @ c:irua:153067UA @ admin @ c:irua:153067 |
Serial |
5117 |
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| Permanent link to this record |
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Author |
Hu, L.; Amini, M.N.; Wu, Y.; Jin, Z.; Yuan, J.; Lin, R.; Wu, J.; Dai, Y.; He, H.; Lu, Y.; Lu, J.; Ye, Z.; Han, S.-T.; Ye, J.; Partoens, B.; Zeng, Y.-J.; Ruan, S. |
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Title |
Charge transfer doping modulated raman scattering and enhanced stability of black phosphorus quantum dots on a ZnO nanorod |
Type |
A1 Journal article |
| |
Year |
2018 |
Publication |
Advanced Optical Materials |
Abbreviated Journal |
Adv Opt Mater |
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| |
Volume |
6 |
Issue |
15 |
Pages |
1800440 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
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Abstract |
Black phosphorus (BP) has recently triggered an unprecedented interest in the 2D community. However, many of its unique properties are not exploited and the well-known environmental vulnerability is not conquered. Herein, a type-I mixed-dimensional (0D-1D) van der Waals heterojunction is developed, where three-atomic-layer BP quantum dots (QDs) are assembled on a single ZnO nanorod (NR). By adjusting the indium (In) content in ZnO NRs, the degree and even the direction of surface charge transfer doping within the heterojunction can be tuned, which result in selective Raman scattering enhancements between ZnO and BP. The maximal enhancement factor is determined as 4340 for BP QDs with sub-ppm level. Furthermore, an unexpected long-term ambient stability (more than six months) of BP QDs is revealed, which is ascribed to the electron doping from ZnO:In NRs. The first demonstration of selective Raman enhancements between two inorganic semiconductors as well as the improved stability of BP shed light on this emerging 2D material. |
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Corporate Author |
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Place of Publication |
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Language |
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Wos |
000440815200023 |
Publication Date |
2018-05-18 |
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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 |
2195-1071 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
6.875 |
Times cited |
37 |
Open Access |
Not_Open_Access |
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Notes |
; L. Hu and M. N. Amini contributed equally to this work. This work was supported by the National Natural Science Foundation of China under Grant Nos. 51502178, 81571763 and 81622026, the Shenzhen Science and Technology Project under Grant Nos. JCYJ20150324141711644, JCYJ20170412105400428, KQJSCX20170727101208249 and JCYJ20170302153853962. Parts of the computational calculations were carried out using the HPC infrastructure at University of Antwerp (CalcUA), a division of the Flemish Supercomputer Center VSC, supported financially by the FWO-Vlaanderen and the Flemish Government (EWI Department). L. H. acknowledges the PhD Start-up Fund of Natural Science Foundation of Guangdong Province under Grand No. 2017A030310072. J. Y. acknowledges the funding of Shanghai Jiao Tong University (Nos. YG2016MS51 and YG2017MS54). ; |
Approved |
Most recent IF: 6.875 |
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| |
Call Number |
UA @ lucian @ c:irua:153112UA @ admin @ c:irua:153112 |
Serial |
5082 |
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Author |
Dabral, A.; Pourtois, G.; Sankaran, K.; Magnus, W.; Yu, H.; de de Meux, A.J.; Lu, A.K.A.; Clima, S.; Stokbro, K.; Schaekers, M.; Collaert, N.; Horiguchi, N.; Houssa, M. |
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Title |
Study of the intrinsic limitations of the contact resistance of metal/semiconductor interfaces through atomistic simulations |
Type |
A1 Journal article |
| |
Year |
2018 |
Publication |
ECS journal of solid state science and technology |
Abbreviated Journal |
Ecs J Solid State Sc |
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| |
Volume |
7 |
Issue |
6 |
Pages |
N73-N80 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
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Abstract |
In this contribution, we report a fundamental study of the factors that set the contact resistivity between metals and highly doped n-type 2D and 3D semiconductors. We investigate the case of n-type doped Si contacted with amorphous TiSi combining first principles calculations with Non-Equilibrium Green functions transport simulations. The evolution of the intrinsic contact resistivity with the doping concentration is found to saturate at similar to 2 x 10(-10) Omega.cm(2) for the case of TiSi and imposes an intrinsic limit to the ultimate contact resistance achievable for n-doped Silamorphous-TiSi (aTiSi). The limit arises from the intrinsic properties of the semiconductors and of the metals such as their electron effective masses and Fermi energies. We illustrate that, in this regime, contacting heavy electron effective mass metals with semiconductor helps reducing the interface intrinsic contact resistivity. This observation seems to hold true regardless of the 3D character of the semiconductor, as illustrated for the case of three 2D semiconducting materials, namely MoS2, ZrS2 and HfS2. (C) The Author(s) 2018. Published by ECS. |
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Corporate Author |
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Thesis |
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Publisher |
Electrochemical society |
Place of Publication |
Pennington (N.J.) |
Editor |
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Language |
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Wos |
000440836000004 |
Publication Date |
2018-05-25 |
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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 |
2162-8769; 2162-8777 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
1.787 |
Times cited |
2 |
Open Access |
Not_Open_Access |
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Notes |
; The authors thank the imec core CMOS program members, the European Commission, its TAKEMI5 ECSEL research project and the local authorities for their support. ; |
Approved |
Most recent IF: 1.787 |
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Call Number |
UA @ lucian @ c:irua:153205UA @ admin @ c:irua:153205 |
Serial |
5130 |
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| Permanent link to this record |
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Author |
Abdullah, H.M.; Bahlouli, H.; Peeters, F.M.; Van Duppen, B. |
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Title |
Confined states in graphene quantum blisters |
Type |
A1 Journal article |
| |
Year |
2018 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
J Phys-Condens Mat |
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Volume |
30 |
Issue |
38 |
Pages |
385301 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Bilayer graphene samples may exhibit regions where the two layers are locally delaminated forming a so-called quanttun blister in the graphene sheet. Electron and hole states can be confined in this graphene quantum blisters (GQB) by applying a global electrostatic bias. We scrutinize the electronic properties of these confined states under the variation of interlayer bias, coupling, and blister's size. The spectra display strong anti-crossings due to the coupling of the confined states on upper and lower layers inside the blister. These spectra are layer localized where the respective confined states reside on either layer or equally distributed. For finite angular momentum, this layer localization can be at the edge of the blister and corresponds to degenerate modes of opposite momenta. Furthermore, the energy levels in GQB exhibit electron-hole symmetry that is sensitive to the electrostatic bias. Finally, we demonstrate that confinement in GQB persists even in the presence of a variation in the interlayer coupling. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
London |
Editor |
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Language |
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Wos |
000443135000001 |
Publication Date |
2018-08-13 |
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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 |
0953-8984 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.649 |
Times cited |
6 |
Open Access |
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Notes |
; HMA and HB acknowledge the Saudi Center for Theoretical Physics (SCTP) for their generous support and the support of KFUPM under physics research group projects RG1502-1 and RG1502-2. This work is supported by the Flemish Science Foundation (FWO-Vl) by a post-doctoral fellowship (BVD). ; |
Approved |
Most recent IF: 2.649 |
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Call Number |
UA @ lucian @ c:irua:153620UA @ admin @ c:irua:153620 |
Serial |
5086 |
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Author |
Van der Donck, M.; Peeters, F.M. |
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Title |
Rich many-body phase diagram of electrons and holes in doped monolayer transition metal dichalcogenides |
Type |
A1 Journal article |
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Year |
2018 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
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Volume |
98 |
Issue |
11 |
Pages |
115432 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
We use a variational technique to study the many-body phase diagram of electrons and holes in n-doped and p-doped monolayer transition metal dichalcogenides (TMDs). We find a total of four different phases. (i) A fully spin polarized and valley polarized ferromagnetic state. (ii) A state with no global spin polarization but with spin polarization in each valley separately, i.e., spin-valley locking. (iii) A state with spin polarization in one of the valleys and little to no spin polarization in the other valley. (iv) A paramagnetic state with no valley polarization. These phases are separated by first-order phase transitions and are determined by the particle density and the dielectric constant of the substrate. We find that in the presence of a perpendicular magnetic field the four different phases persist. In the case of n-doped MoS2, a fifth phase, which is completely valley polarized but not spin polarized, appears for magnetic fields larger than 7 T and for magnetic fields larger than 23 T completely replaces the second phase. |
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Address |
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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 |
000445507000009 |
Publication Date |
2018-09-24 |
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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 |
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 |
8 |
Open Access |
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Notes |
; This work was supported by the Research Foundation of Flanders (FWO-Vl) through an aspirant research grant for MVDD and by the FLAG-ERA project TRANS-2D-TMD. ; |
Approved |
Most recent IF: 3.836 |
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Call Number |
UA @ lucian @ c:irua:153622UA @ admin @ c:irua:153622 |
Serial |
5125 |
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Author |
Dong, H.M.; Xu, W.; Peeters, F.M. |
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Title |
Electrical generation of terahertz blackbody radiation from graphene |
Type |
A1 Journal article |
| |
Year |
2018 |
Publication |
Optics express |
Abbreviated Journal |
Opt Express |
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| |
Volume |
26 |
Issue |
19 |
Pages |
24621-24626 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Recent experimental work on the application of graphene for novel illumination motivated us to present a theoretical study of the blackbody radiation emission from a freely suspended graphene driven by a dc electric field. Strong terahertz (THz) emission, with intensity up to mW/cm(2), can be generated with increasing electric field strength due to the heating of electrons in graphene. We show that the intensity of the THz emission generated electrically from graphene depends rather sensitively on the lattice temperature in relatively weak electric fields, whereas it is less sensitive to the lattice temperature in relative strong electric fields. Our study highlights the practical application of graphene as intense THz source where the radiation is generated electrically. (C) 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement |
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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 |
000444705000026 |
Publication Date |
2018-09-05 |
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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 |
1094-4087 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.307 |
Times cited |
14 |
Open Access |
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Notes |
; National Natural Science Foundation of China (NSFC) (11604380, 11574319); Center of Science and Technology of Hefei Academy of Science (2016FXZY002); Department of Science and Technology of Yunnan Province (2016FC001). ; |
Approved |
Most recent IF: 3.307 |
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Call Number |
UA @ lucian @ c:irua:153632UA @ admin @ c:irua:153632 |
Serial |
5095 |
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| Permanent link to this record |
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Author |
Nakhaee, M.; Ketabi, S.A.; Peeters, F.M. |
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Title |
Dirac nodal line in bilayer borophene : tight-binding model and low-energy effective Hamiltonian |
Type |
A1 Journal article |
| |
Year |
2018 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
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| |
Volume |
98 |
Issue |
11 |
Pages |
115413 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Bilayer hexagonal borophene, which is bound together through pillars, is a novel topological semimetal. Using density functional theory, we investigate its electronic band structure and show that it is a Dirac material which exhibits a nodal line. A tight-binding model was constructed based on the Slater-Koster approach, which accurately models the electronic spectrum. We constructed an effective four-band model Hamiltonian to describe the spectrum near the nodal line. This Hamiltonian can be used as a new platform to study the new properties of nodal line semimetals. We found that the nodal line is created by edge states and is very robust against perturbations and impurities. Breaking symmetries can split the nodal line, but cannot open a gap. |
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Address |
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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 |
000443916200007 |
Publication Date |
2018-09-06 |
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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 |
19 |
Open Access |
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Notes |
; This work was supported by the Methusalem program of the Flemish government and the graphene FLAG-ERA project TRANS-2D-TMD. ; |
Approved |
Most recent IF: 3.836 |
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Call Number |
UA @ lucian @ c:irua:153649UA @ admin @ c:irua:153649 |
Serial |
5090 |
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| Permanent link to this record |
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Author |
Van der Donck, M.; Peeters, F.M. |
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Title |
Interlayer excitons in transition metal dichalcogenide heterostructures |
Type |
A1 Journal article |
| |
Year |
2018 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
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| |
Volume |
98 |
Issue |
11 |
Pages |
115104 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Starting from the single-particle Dirac Hamiltonian for charge carriers in monolayer transition metal dichalcogenides (TMDs), we construct a four-band Hamiltonian describing interlayer excitons consisting of an electron in one TMD layer and a hole in the other TMD layer. An expression for the electron-hole interaction potential is derived, taking into account the effect of the dielectric environment above, below, and between the two TMD layers as well as polarization effects in the transition metal layer and in the chalcogen layers of the TMD layers. We calculate the interlayer exciton binding energy and average in-plane interparticle distance for different TMD heterostructures. The effect of different dielectric environments on the exciton binding energy is investigated and a remarkable dependence on the dielectric constant of the barrier between the two layers is found, resulting from competing effects as a function of the in-plane and out-of-plane dielectric constants of the barrier. The polarization effects in the chalcogen layers, which in general reduce the exciton binding energy, can lead to an increase in binding energy in the presence of strong substrate effects by screening the substrate. The excitonic absorbance spectrum is calculated and we show that the interlayer exciton peak depends linearly on a perpendicular electric field, which agrees with recent experimental results. |
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Address |
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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 |
000443671900004 |
Publication Date |
2018-09-04 |
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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 |
41 |
Open Access |
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| |
Notes |
; This work was supported by the Research Foundation of Flanders (FWO-Vl) through an aspirant research grant for MVDD and by the FLAG-ERA project TRANS-2D-TMD. ; |
Approved |
Most recent IF: 3.836 |
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| |
Call Number |
UA @ lucian @ c:irua:153653UA @ admin @ c:irua:153653 |
Serial |
5110 |
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| Permanent link to this record |
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Author |
Van Pottelberge, R.; Zarenia, M.; Peeters, F.M. |
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Title |
Magnetic field dependence of atomic collapse in bilayer graphene |
Type |
A1 Journal article |
| |
Year |
2018 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
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| |
Volume |
98 |
Issue |
11 |
Pages |
115406 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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| |
Abstract |
The spectrum of a Coulomb impurity in bilayer graphene is investigated as function of the strength of a perpendicular magnetic field for different values of the angular quantum number m and for different values of the gate voltage. We point out fundamental differences between the results from the two-band and four-band model. The supercritical instability and fall-to-center phenomena are investigated in the presence of a magnetic field. We find that in the four-band model the fall-to-center phenomenon occurs as in monolayer graphene, while this is not the case in the two-band model. We find that in a magnetic field the supercritical instability manifests itself as a series of anticrossings in the hole part of the spectrum for states coming from the low-energy band. However, we also find very distinct anticrossings in the electron part of the spectrum that continue into the hole part, which are related to the higher energy band of the four-band model. At these anticrossings, we find a very sharp peak in the probability density close to the impurity, reminiscent for the fall-to-center phenomenon. In this paper, these peculiar and interesting effects are studied for different magnetic field, interlayer coupling, and bias potential strengths. |
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Address |
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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 |
000443671900010 |
Publication Date |
2018-09-04 |
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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 |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.836 |
Times cited |
3 |
Open Access |
|
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| |
Notes |
; We thank Matthias Van der Donck and Ben Van Duppen for fruitful discussions. This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem funding of the Flemish Government. ; |
Approved |
Most recent IF: 3.836 |
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| |
Call Number |
UA @ lucian @ c:irua:153654UA @ admin @ c:irua:153654 |
Serial |
5113 |
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| Permanent link to this record |
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Author |
Mulkers, J.; Hals, K.M.D.; Leliaert, J.; Milošević, M.V.; Van Waeyenberge, B.; Everschor-Sitte, K. |
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| |
Title |
Effect of boundary-induced chirality on magnetic textures in thin films |
Type |
A1 Journal article |
| |
Year |
2018 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
|
| |
Volume |
98 |
Issue |
6 |
Pages |
064429 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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| |
Abstract |
In the quest for miniaturizing magnetic devices, the effects of boundaries and surfaces become increasingly important. Here we show how the recently predicted boundary-induced Dzyaloshinskii-Moriya interaction (DMI) affects the magnetization of ferromagnetic films with a C-infinity v symmetry and a perpendicular magnetic anisotropy. For an otherwise uniformly magnetized film, we find a surface twist when the magnetization in the bulk is canted by an in-plane external field. This twist at the surfaces caused by the boundary-induced DMI differs from the common canting caused by internal DMI observed at the edges of a chiral magnet. Furthermore, we find that the surface twist due to the boundary-induced DMI strongly affects the width of the domain wall at the surfaces. We also find that the skyrmion radius increases in the depth of the film, with the average size of the skyrmion increasing with boundary-induced DMI. This increase suggests that the boundary-induced DMI contributes to the stability of the skyrmion. |
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Address |
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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 |
000443394600004 |
Publication Date |
2018-08-31 |
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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 |
|
|
| |
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 |
|
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| |
Notes |
; The authors thank Matthias Sitte and Andre Thiaville for fruitful discussions. This work was supported by the Fonds Wetenschappelijk Onderzoek (FWO-Vlaanderen) through Project No. G098917N and the German Research Foundation (DFG) under the Project No. EV 196/2-1. J.L. is supported by the Ghent University Special Research Fund with a BOF postdoctoral fellowship. ; |
Approved |
Most recent IF: 3.836 |
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| |
Call Number |
UA @ lucian @ c:irua:153706UA @ admin @ c:irua:153706 |
Serial |
5093 |
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| Permanent link to this record |
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| |
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Author |
Kandemir, A.; Peeters, F.M.; Sahin, H. |
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| |
Title |
Monitoring the effect of asymmetrical vertical strain on Janus single layers of MoSSe via spectrum |
Type |
A1 Journal article |
| |
Year |
2018 |
Publication |
The journal of chemical physics |
Abbreviated Journal |
J Chem Phys |
|
| |
Volume |
149 |
Issue |
8 |
Pages |
084707 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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| |
Abstract |
Using first principles calculations, we study the structural and phononic properties of the recently synthesized Janus type single layers of molybdenum dichalcogenides. The Janus MoSSe single layer possesses 2H crystal structure with two different chalcogenide sides that lead to out-of-plane anisotropy. By virtue of the asymmetric structure of the ultra-thin Janus type crystal, we induced the out-of-plane anisotropy to show the distinctive vertical pressure effect on the vibrational properties of the Janus material. It is proposed that for the corresponding Raman active optical mode of the Janus structure, the phase modulation and the magnitude ratio of the strained atom and its first neighbor atom adjust the distinctive change in the eigen-frequencies and Raman activity. Moreover, a strong variation in the Raman activity of the Janus structure is obtained under bivertical and univertical strains. Not only eigen-frequency shifts but also Raman activities of the optical modes of the Janus structure exhibit distinguishable features. This study reveals that the vertical anisotropic feature of the Janus structure under Raman measurement allows us to distinguish which side of the Janus crystal interacts with the externals (substrate, functional adlayers, or dopants). Published by AIP Publishing. |
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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 |
New York, N.Y. |
Editor |
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| |
Language |
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Wos |
000444035800044 |
Publication Date |
2018-08-30 |
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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 |
0021-9606 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
2.965 |
Times cited |
11 |
Open Access |
|
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| |
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 No. 117F095. F.M.P. was supported by the FLAG-ERA-TRANS<INF>2D</INF>TMD. ; |
Approved |
Most recent IF: 2.965 |
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| |
Call Number |
UA @ lucian @ c:irua:153711UA @ admin @ c:irua:153711 |
Serial |
5115 |
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| Permanent link to this record |
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Author |
Yagmurcukardes, M.; Peeters, F.M.; Sahin, H. |
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| |
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) |
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| |
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. |
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| |
Address |
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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 |
|
Wos |
000442667200008 |
Publication Date |
2018-08-24 |
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Series Editor |
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Series Title |
|
Abbreviated Series Title |
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Series Volume |
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Series Issue |
|
Edition |
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| |
ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.836 |
Times cited |
41 |
Open Access |
|
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| |
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 |
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| |
Call Number |
UA @ lucian @ c:irua:153716UA @ admin @ c:irua:153716 |
Serial |
5097 |
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| Permanent link to this record |
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Author |
Torun, E.; Sahin, H.; Chaves, A.; Wirtz, L.; Peeters, F.M. |
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| |
Title |
Ab initio and semiempirical modeling of excitons and trions in monolayer TiS3 |
Type |
A1 Journal article |
| |
Year |
2018 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
|
| |
Volume |
98 |
Issue |
7 |
Pages |
075419 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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| |
Abstract |
We explore the electronic and the optical properties of monolayer TiS3, which shows in-plane anisotropy and is composed of a chain-like structure along one of the lattice directions. Together with its robust direct band gap, which changes very slightly with stacking order and with the thickness of the sample, the anisotropic physical properties of TiS3 make the material very attractive for various device applications. In this study, we present a detailed investigation on the effect of the crystal anisotropy on the excitons and the trions of the TiS3 monolayer. We use many-body perturbation theory to calculate the absorption spectrum of anisotropic TiS3 monolayer by solving the Bethe-Salpeter equation. In parallel, we implement and use a Wannier-Mott model for the excitons that takes into account the anisotropic effective masses and Coulomb screening, which are obtained from ab initio calculations. This model is then extended for the investigation of trion states of monolayer TiS3. Our calculations indicate that the absorption spectrum of monolayer TiS3 drastically depends on the polarization of the incoming light, which excites different excitons with distinct binding energies. In addition, the binding energies of positively and the negatively charged trions are observed to be distinct and they exhibit an anisotropic probability density distribution. |
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Address |
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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 |
000442342100002 |
Publication Date |
2018-08-21 |
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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 |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.836 |
Times cited |
10 |
Open Access |
|
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| |
Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl) and the FLAG-ERA project TRANS-2D-TMD. H.S. acknowledges financial support from TUBITAK under Project No. 117F095. A.C. acknowledges support from the Brazilian Research Council (CNPq), through the PRONEX/FUNCAP and Science Without Borders programs, and from the Lemann Foundation. E.T. and L.W. acknowledge support from the National Research Fund, Luxembourg (IN-TER/ANR/13/20/NANOTMD). ; |
Approved |
Most recent IF: 3.836 |
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| |
Call Number |
UA @ lucian @ c:irua:153721UA @ admin @ c:irua:153721 |
Serial |
5076 |
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| Permanent link to this record |
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Author |
Bizindavyi, J.; Verhulst, A.S.; Sorée, B.; Groeseneken, G. |
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Title |
Impact of calibrated band-tails on the subthreshold swing of pocketed TFETs |
Type |
P1 Proceeding |
| |
Year |
2018 |
Publication |
Conference digest
T2 – 76th Device Research Conference (DRC), JUN 24-27, 2018, Santa Barbara, CA |
Abbreviated Journal |
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| |
Volume |
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Issue |
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Pages |
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Keywords |
P1 Proceeding; Condensed Matter Theory (CMT) |
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Abstract |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
Ieee |
Place of Publication |
New york |
Editor |
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Language |
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Wos |
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Publication Date |
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Series Editor |
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Series Title |
|
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 |
978-1-5386-3028-0 |
ISBN |
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Additional Links |
UA library record; WoS full record |
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Impact Factor |
|
Times cited |
|
Open Access |
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Notes |
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Approved |
Most recent IF: NA |
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| |
Call Number |
UA @ lucian @ c:irua:153780 |
Serial |
5106 |
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| Permanent link to this record |
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| |
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Author |
Bizindavyi, J.; Verhulst, A.S.; Sorée, B.; Groeseneken, G. |
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| |
Title |
Impact of calibrated band-tails on the subthreshold swing of pocketed TFETs |
Type |
P1 Proceeding |
| |
Year |
2018 |
Publication |
Conference digest
T2 – 76th Device Research Conference (DRC), JUN 24-27, 2018, Santa Barbara, CA |
Abbreviated Journal |
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| |
Volume |
|
Issue |
|
Pages |
|
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| |
Keywords |
P1 Proceeding; Condensed Matter Theory (CMT) |
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Abstract |
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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 |
000444728400086 |
Publication Date |
2018-09-07 |
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| |
Series Editor |
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Series Title |
|
Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
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| |
ISSN |
978-1-5386-3028-0 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
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| |
Impact Factor |
|
Times cited |
|
Open Access |
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| |
Notes |
|
Approved |
Most recent IF: NA |
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| |
Call Number |
UA @ admin @ c:irua:153780 |
Serial |
5217 |
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| Permanent link to this record |
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Author |
Gul, A.; Bacaksiz, C.; Unsal, E.; Akbali, B.; Tomak, A.; Zareie, H.M.; Sahin, H. |
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| |
Title |
Theoretical and experimental investigation of conjugation of 1,6-hexanedithiol on MoS2 |
Type |
A1 Journal article |
| |
Year |
2018 |
Publication |
Materials Research Express |
Abbreviated Journal |
Mater Res Express |
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| |
Volume |
5 |
Issue |
3 |
Pages |
036415 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
We report an experimental and theoretical investigation of conjugation of 1,6-Hexaneditihiol (HDT) on MoS2 which is prepared by mixing MoS2 structure and HDT molecules in proper solvent. Raman spectra and the calculated phonon bands reveal that the HDT molecules bind covalently to MoS2. Surface morphology of MoS2/HDTstructure is changed upon conjugation ofHDTon MoS2 and characterized by using Scanning Electron Microscope (SEM). Density Functional Theory (DFT) based calculations show that HOMO-LUMO band gap of HDT is altered after the conjugation and two-S binding (handle-like) configuration is energetically most favorable among three different structures. This study displays that the facile thiol functionalization process of MoS2 is promising strategy for obtaining solution processable MoS2. |
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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 |
000428781400003 |
Publication Date |
2018-03-07 |
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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 |
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Edition |
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| |
ISSN |
2053-1591 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
1.068 |
Times cited |
2 |
Open Access |
|
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| |
Notes |
; Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure). HS acknowledges financial support from the TUBITAK under the project number 116C073. HS acknowledges support from Bilim Akademisi-The Science Academy, Turkey under the BAGEP program. ; |
Approved |
Most recent IF: 1.068 |
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| |
Call Number |
UA @ lucian @ c:irua:154607UA @ admin @ c:irua:154607 |
Serial |
5133 |
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| Permanent link to this record |
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Author |
Aydin, H.; Bacaksiz, C.; Yagmurcukardes, N.; Karakaya, C.; Mermer, O.; Can, M.; Senger, R.T.; Sahin, H.; Selamet, Y. |
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Title |
Experimental and computational investigation of graphene/SAMs/n-Si Schottky diodes |
Type |
A1 Journal article |
| |
Year |
2018 |
Publication |
Applied Surface Science |
Abbreviated Journal |
Appl Surf Sci |
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| |
Volume |
428 |
Issue |
428 |
Pages |
1010-1017 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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| |
Abstract |
We have investigated the effect of two different self-assembled monolayers (SAMs) on electrical characteristics of bilayer graphene (BLG)/n-Si Schottky diodes. Novel 4“bis(diphenylamino)-1, 1':3”-terpheny1-5' carboxylic acids (TPA) and 4,4-di-9H-carbazol-9-y1-1,1':3'1'-terpheny1-5' carboxylic acid (CAR) aromatic SAMs have been used to modify n-Si surfaces. Cyclic voltammetry (CV) and Kelvin probe force microscopy (KPFM) results have been evaluated to verify the modification of n-Si surface. The current-voltage (I-V) characteristics of bare and SAMs modified devices show rectification behaviour verifying a Schottky junction at the interface. The ideality factors (n) from ln(I)-V dependences were determined as 2.13,1.96 and 2.07 for BLG/n-Si, BLG/TPA/n-Si and BLG/CAR/n-Si Schottky diodes, respectively. In addition, Schottky barrier height (SBH) and series resistance (Rs) of SAMs modified diodes were decreased compared to bare diode due to the formation of a compatible interface between graphene and Si as well as n-n interaction between aromatic SAMs and graphene. The CAR-based device exhibits better diode characteristic compared to the TPA-based device. Computational simulations show that the BLG/CAR system exhibits smaller energy-level-differences than the BLG/TPA, which supports the experimental findings of a lower Schottky barrier and series resistance in BLG/CAR diode. (C) 2017 Elsevier B.V. All rights reserved. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
Amsterdam |
Editor |
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| |
Language |
|
Wos |
000415227000128 |
Publication Date |
2017-09-29 |
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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 |
0169-4332 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.387 |
Times cited |
2 |
Open Access |
|
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| |
Notes |
; This work was supported by TUBITAK (The Scientific and Technical Research Council of Turkey) with project number 112T946. We also thank AQuReC (Applied Quantum Research Center) for Raman measurements. 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. ; |
Approved |
Most recent IF: 3.387 |
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| |
Call Number |
UA @ lucian @ c:irua:154608UA @ admin @ c:irua:154608 |
Serial |
5101 |
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| Permanent link to this record |
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Author |
Van Pottelberge, R.; Van Duppen, B.; Peeters, F.M. |
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| |
Title |
Electrical dipole on gapped graphene : bound states and atomic collapse |
Type |
A1 Journal article |
| |
Year |
2018 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
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| |
Volume |
98 |
Issue |
16 |
Pages |
165420 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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| |
Abstract |
We investigate the energy spectrum, wave functions, and local density of states of an electrical dipole placed on a sheet of gapped graphene as function of the charge strength Z alpha for different sizes of the dipole and for different regularization parameters. The dipole is modeled as consisting of a positive and negative charge. Bound states are found within the gap region with some energy levels that anticross and others that cross as function of the impurity strength Z alpha. The anticrossings are more pronounced and move to higher charges Z alpha when the length of the dipole decreases. These energy levels turn into atomic collapse states when they enter the positive (or negative) energy continuum. A smooth transition from the single-impurity behavior to the dipole one is observed: The states diving towards the continuum in the single-impurity case are gradually replaced by a series of anticrossings that represent a continuation of the diving states in the single-impurity case. By studying the local density of states at the edge of the dipole we show how the series of anticrossings persist in the positive and negative continuum. |
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Address |
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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 |
|
Wos |
000447302700010 |
Publication Date |
2018-10-23 |
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| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
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| |
ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
3.836 |
Times cited |
8 |
Open Access |
|
|
| |
Notes |
; We thank Matthias Van der Donck for fruitful discussions. This work was supported by the Research Foundation of Flanders (FWO-V1) through an aspirant research grant for R.V.P. and a postdoctoral grant for B.V.D. ; |
Approved |
Most recent IF: 3.836 |
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| |
Call Number |
UA @ lucian @ c:irua:154728UA @ admin @ c:irua:154728 |
Serial |
5094 |
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| Permanent link to this record |
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Author |
Beckers, A.; Thewissen, M.; Sorée, B. |
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Title |
Energy filtering in silicon nanowires and nanosheets using a geometric superlattice and its use for steep-slope transistors |
Type |
A1 Journal article |
| |
Year |
2018 |
Publication |
Journal of applied physics |
Abbreviated Journal |
J Appl Phys |
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| |
Volume |
124 |
Issue |
14 |
Pages |
144304 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
This paper investigates energy filtering in silicon nanowires and nanosheets by resonant electron tunneling through a geometric superlattice. A geometric superlattice is any kind of periodic geometric feature along the transport direction of the nanowire or nanosheet. Multivalley quantum-transport simulations are used to demonstrate the manifestation of minibands and minibandgaps in the transmission spectra of such a superlattice. We find that the presence of different valleys in the conduction band of silicon favors a nanowire with a rectangular cross section for effective energy filtering. The obtained energy filter can consequently be used in the source extension of a field-effect transistor to prevent high-energy electrons from contributing to the leakage current. Self-consistent Schrodinger-Poisson simulations in the ballistic limit show minimum subthreshold swings of 6 mV/decade for geometric superlattices with indentations. The obtained theoretical performance metrics for the simulated devices are compared with conventional III-V superlatticeFETs and TunnelFETs. The adaptation of the quantum transmitting boundary method to the finite-element simulation of 3-D structures with anisotropic effective mass is presented in Appendixes A and B. Our results bare relevance in the search for steep-slope transistor alternatives which are compatible with the silicon industry and can overcome the power-consumption bottleneck inherent to standard CMOS technologies. Published by AIP Publishing. |
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Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
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Wos |
000447148100011 |
Publication Date |
2018-10-11 |
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Abbreviated Series Title |
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Edition |
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ISSN |
0021-8979; 1089-7550 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.068 |
Times cited |
3 |
Open Access |
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Notes |
; ; |
Approved |
Most recent IF: 2.068 |
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Call Number |
UA @ lucian @ c:irua:154729UA @ admin @ c:irua:154729 |
Serial |
5099 |
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Author |
de Aquino, B.R.C.H.T. |
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Title |
Carbon nanotubes and graphene based devices : from nanosensors to confined water |
Type |
Doctoral thesis |
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Year |
2018 |
Publication |
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Abbreviated Journal |
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Volume |
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Pages |
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Keywords |
Doctoral thesis; Condensed Matter Theory (CMT) |
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Impact Factor |
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Times cited |
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Open Access |
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Notes |
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Approved |
Most recent IF: NA |
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Call Number |
UA @ lucian @ c:irua:154838 |
Serial |
5081 |
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Author |
de Aquino, B.R.C.H.T. |
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Title |
Carbon nanotubes and graphene based devices : from nanosensors to confined water |
Type |
Doctoral thesis |
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Year |
2018 |
Publication |
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Abbreviated Journal |
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Volume |
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Issue |
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Pages |
161 p. |
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Keywords |
Doctoral thesis; Condensed Matter Theory (CMT) |
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Additional Links |
UA library record |
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Impact Factor |
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Times cited |
|
Open Access |
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Notes |
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Approved |
Most recent IF: NA |
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Call Number |
UA @ admin @ c:irua:154838 |
Serial |
5197 |
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Author |
Leliaert, J.; Gypens, P.; Milošević, M.V.; Van Waeyenberge, B.; Mulkers, J. |
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Title |
Coupling of the skyrmion velocity to its breathing mode in periodically notched nanotracks |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Journal of physics: D: applied physics |
Abbreviated Journal |
J Phys D Appl Phys |
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Volume |
52 |
Issue |
2 |
Pages |
024003 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
A thorough understanding of the skyrmion motion through nanotracks is a prerequisite to realize the full potential of spintronic applications like the skyrmion racetrack memory. One of the challenges is to place the data, i.e. skyrmions, on discrete fixed positions, e.g. below a read or write head. In the domain-wall racetrack memory, one proposed solution to this problem was patterning the nanotrack with notches. Following this approach, this paper reports on the skyrmion mobility through a nanotrack with periodic notches (constrictions) made using variations in the chiral Dzyaloshinskii-Moriya interaction. We observe that such notches induce a coupling between the mobility and the skyrmion breathing mode, which manifests itself as velocity-dependent oscillations of the skyrmion diameter and plateaus in which the velocity is independent of the driving force. Despite the fact that domain walls are far more rigid objects than skyrmions, we were able to perform an analogous study and, surprisingly, found even larger plateaus of constant velocity. For both systems it is straightforward to tune the velocity at these plateaus by changing the design of the notched nanotrack geometry, e.g. by varying the distance between the notches. Therefore, the notch-induced coupling between the excited modes and the mobility could offer a strategy to stabilize the velocity against unwanted perturbations in racetrack-like applications. In the last part of the paper we focus on the low-current mobility regimes, whose very rich dynamics at nonzero temperatures are very similar to the operating principle of recently developed probabilistic logic devices. This proves that the mobility of nanomagnetic structures through a periodically modulated track is not only interesting from a fundamental point of view, but has a future in many spintronic applications. |
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Wos |
000449169100001 |
Publication Date |
2018-10-11 |
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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 |
0022-3727 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.588 |
Times cited |
10 |
Open Access |
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Notes |
; This work is supported by Fonds Wetenschappelijk Onderzoek (FWO-Vlaanderen) through Project No. G098917N. JL acknowledges his postdoctoral fellowships by the Ghent University special research fund (BOF) and FWO-Vlaanderen. The authors gratefully acknowledge the support of NVIDIA Corporation through donation of Titan Xp and Titan V GPU cards used for this research. ; |
Approved |
Most recent IF: 2.588 |
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Call Number |
UA @ admin @ c:irua:155359 |
Serial |
5202 |
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Author |
Li, L.; Kong, X.; Peeters, F.M. |
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Title |
New nanoporous graphyne monolayer as nodal line semimetal : double Dirac points with an ultrahigh Fermi velocity |
Type |
A1 Journal article |
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Year |
2019 |
Publication |
Carbon |
Abbreviated Journal |
Carbon |
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Volume |
141 |
Issue |
141 |
Pages |
712-718 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Two-dimensional (2D) carbon materials play an important role in nanomaterials. We propose a new carbon monolayer, named hexagonal-4,4,4-graphyne (H-4,H-4,H-4-graphyne), which is a nanoporous structure composed of rectangular carbon rings and triple bonds of carbon. Using first-principles calculations, we systematically studied the structure, stability, and band structure of this new material. We found that its total energy is lower than that of experimentally synthesized beta-graphdiyne and it is stable at least up to 1500 K. In contrast to the single Dirac point band structure of other 2D carbon monolayers, the band structure of H-4,H-4,H-4-graphyne exhibits double Dirac points along the high-symmetry points and the corresponding Fermi velocities (1.04-1.27 x 10(6) m/s) are asymmetric and higher than that of graphene. The origin of these double Dirac points is traced back to the nodal line states, which can be well explained by a tight-binding model. The H-4,H-4,H-4-graphyne forms a moire superstructure when placed on top of a hexagonal boron nitride substrate. These properties make H-4,H-4,H-4-graphyne a promising semimetal material for applications in high-speed electronic devices. (C) 2018 Elsevier Ltd. All rights reserved. |
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Wos |
000450312600072 |
Publication Date |
2018-10-01 |
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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 |
0008-6223 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
6.337 |
Times cited |
38 |
Open Access |
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Notes |
; This work was supported by the Fonds voor Wetenschappelijk Onderzoek (FWO-Vl), and the FLAG-ERA project TRANS2DTMD. The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center), funded by the Research Foundation – Flanders (FWO) and the Flemish Government -department EWI. ; |
Approved |
Most recent IF: 6.337 |
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Call Number |
UA @ admin @ c:irua:155364 |
Serial |
5222 |
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Author |
Callewaert, V. |
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Title |
Development and application of a non-local theory for the description of positron surface states |
Type |
Doctoral thesis |
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Year |
2018 |
Publication |
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Abbreviated Journal |
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Volume |
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Issue |
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Pages |
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Keywords |
Doctoral thesis; Condensed Matter Theory (CMT) |
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Additional Links |
UA library record |
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Impact Factor |
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Times cited |
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Notes |
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Approved |
Most recent IF: NA |
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Call Number |
UA @ lucian @ c:irua:155688 |
Serial |
5089 |
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Author |
Callewaert, V. |
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Title |
Development and application of a non-local theory for the description of positron surface states |
Type |
Doctoral thesis |
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Year |
2018 |
Publication |
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Abbreviated Journal |
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Volume |
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Issue |
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Pages |
151 p. |
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Keywords |
Doctoral thesis; Condensed Matter Theory (CMT) |
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Additional Links |
UA library record |
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Impact Factor |
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Times cited |
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Open Access |
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Notes |
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Approved |
Most recent IF: NA |
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Call Number |
UA @ admin @ c:irua:155688 |
Serial |
5204 |
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Author |
Badalov, S.V.; Yagmurcukardes, M.; Peeters, F.M.; Sahin, H. |
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Title |
Enhanced stability of single-layer w-Gallenene through hydrogenation |
Type |
A1 Journal article |
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Year |
2018 |
Publication |
The journal of physical chemistry: C : nanomaterials and interfaces |
Abbreviated Journal |
J Phys Chem C |
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Volume |
122 |
Issue |
49 |
Pages |
28302-28309 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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Abstract |
Using density functional theory based first-principles calculations, the effect of surface hydrogenation on the structural, dynamical, electronic, and mechanical properties of monolayer washboard-gallenene (w-gallenene) is investigated. It is found that the dynamically stabilized strained monolayer of w-gallenene has a metallic nonmagnetic ground state. Both one-sided and two-sided hydrogenations of w-gallenene suppress its dynamical instability even when unstrained. Unlike one-sided hydrogenated monolayer w-gallenene (os-w-gallenene), two-sided hydrogenated monolayer w-gallenene (ts-w-gallenene) possesses the same crystal structure as w-gallenene. Electronic band structure calculations reveal that monolayers of hydrogenated derivatives of w-gallenene exhibit also metallic nonmagnetic ground state. Moreover, the linear-elastic constants, in-plane stiffness and Poisson ratio, are enhanced by hydrogenation, which is opposite to the behavior of other hydrogenated monolayer crystals. Furthermore, monolayer w-gallenene and ts-w-gallenene remain dynamically stable up to relatively higher biaxial strains as compared to borophene. With its enhanced dynamical stability, robust metallic character, and enhanced linear-elastic properties, hydrogenated monolayer w-gallenene is a potential candidate for nanodevice applications as a two-dimensional flexible metal. |
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Wos |
000453488300053 |
Publication Date |
2018-11-12 |
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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 |
20 |
Open Access |
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Notes |
; Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure). H.S. acknowledges support from Turkish Academy of Sciences under the GEBIP program. This work was supported by FLAG-ERA project TRANS-2D-TMD. This work is supported by the Flemish Science Foundation (FWO-Vl) by a postdoctoral fellowship (M.Y.). ; |
Approved |
Most recent IF: 4.536 |
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Call Number |
UA @ admin @ c:irua:156229 |
Serial |
5210 |
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Author |
Saberi-Pouya, S.; Zarenia, M.; Vazifehshenas, T.; Peeters, F.M. |
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Title |
Anisotropic charge density wave in electron-hole double monolayers : applied to phosphorene |
Type |
A1 Journal article |
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Year |
2018 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
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Volume |
98 |
Issue |
24 |
Pages |
245115 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
The possibility of an inhomogeneous charge density wave phase is investigated in a system of two coupled electron and hole monolayers separated by a hexagonal boron nitride insulating layer. The charge-density-wave state is induced through the assumption of negative compressibility of electron/hole gases in a Coulomb drag configuration between the electron and hole sheets. Under equilibrium conditions, we derive analytical expressions for the density oscillation along the zigzag and armchair directions. We find that the density modulation not only depends on the sign of the compressibility but also on the anisotropy of the low-energy bands. Our results are applicable to any two-dimensional system with anisotropic parabolic bands, characterized by different effective masses. For equal effective masses, i.e., isotropic energy bands, our results agree with Hroblak et al. [Phys. Rev. B 96, 075422 (2017)]. Our numerical results are applied to phosphorene. |
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Wos |
000452995600001 |
Publication Date |
2018-12-12 |
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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 |
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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 |
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Impact Factor |
3.836 |
Times cited |
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Open Access |
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Notes |
; This work was partially supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem program of the Flemish government and Iran Science Elites Federation. ; |
Approved |
Most recent IF: 3.836 |
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Call Number |
UA @ admin @ c:irua:156233 |
Serial |
5195 |
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Author |
De Sloovere, D.; Safari, M.; Elen, K.; D'Haen, J.; Drozhzhin, O.A.; Abakumov, A.M.; Simenas, M.; Banys, J.; Bekaert, J.; Partoens, B.; Van Bael, M.K.; Hardy, A. |
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Title |
Reduced Na2+xTi4O9 composite : a durable anode for sodium-ion batteries |
Type |
A1 Journal article |
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Year |
2018 |
Publication |
Chemistry of materials |
Abbreviated Journal |
Chem Mater |
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Volume |
30 |
Issue |
23 |
Pages |
8521-8527 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Sodium-ion batteries (SIBs) are potential cost-effective solutions for stationary energy storage applications. Unavailability of suitable anode materials, however, is one of the important barriers to the maturity of SIBs. Here, we report a Na2+xTi4O9/C composite as a promising anode candidate for SIBs with high capacity and cycling stability. This anode is characterized by a capacity of 124 mAh g(-1) (plus 11 mAh g(-1) contributed by carbon black), an average discharge potential of 0.9 V vs Na/Na+, a good rate capability and a high stability (89% capacity retention after 250 cycles at a rate of 1 degrees C). The mechanisms of sodium insertion/deinsertion and of the formation of Na2+xTi4O9/C are investigated with the aid of various ex/in situ characterization techniques. The in situ formed carbon is necessary for the formation of the reduced sodium titanate. This synthesis method may enable the convenient synthesis of other composites of crystalline phases with amorphous carbon. |
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Wos |
000453489300014 |
Publication Date |
2018-11-29 |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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ISSN |
0897-4756 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
9.466 |
Times cited |
7 |
Open Access |
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Notes |
; This work was supported by the FWO (Research Foundation Flanders, project G040116). O.A.D. and A.M.A. are grateful to the Russian Science Foundation for financial support (Grant 17-73-30006). The authors acknowledge Pieter Samyn for Raman spectroscopy, Fulya Ulu Okudur for preliminary TEM, Bart Ruttens for XRD, Hilde Pellaers for SEM, Tom Haeldermans for elemental analysis, and Karen Leyssen and Vera Meynen for physisorption measurements. ; |
Approved |
Most recent IF: 9.466 |
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Call Number |
UA @ admin @ c:irua:156235 |
Serial |
5227 |
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Author |
Van der Donck, M.; Peeters, F.M. |
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Title |
Excitonic complexes in anisotropic atomically thin two-dimensional materials : black phosphorus and TiS3 |
Type |
A1 Journal article |
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Year |
2018 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
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Volume |
98 |
Issue |
23 |
Pages |
235401 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
The effect of anisotropy in the energy spectrum on the binding energy and structural properties of excitons, trions, and biexcitons is investigated. To this end we employ the stochastic variational method with a correlated Gaussian basis. We present results for the binding energy of different excitonic complexes in black phosphorus (bP) and TiS3 and compare them with recent results in the literature when available, for which we find good agreement. The binding energies of excitonic complexes in bP are larger than those in TiS3. We calculate the different average interparticle distances in bP and TiS3 and show that excitonic complexes in bP are strongly anisotropic whereas in TiS3 they are almost isotropic, even though the constituent particles have an anisotropic energy spectrum. This is also confirmed by the correlation functions. |
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Place of Publication |
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Wos |
000452003400009 |
Publication Date |
2018-12-03 |
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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 |
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 |
10 |
Open Access |
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| |
Notes |
; This work was supported by the Research Foundation of Flanders (FWO-Vl) through an aspirant research grant for MVDD and by the FLAG-ERA project TRANS-2D-TMD. ; |
Approved |
Most recent IF: 3.836 |
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Call Number |
UA @ admin @ c:irua:156247 |
Serial |
5211 |
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| Permanent link to this record |
