scholarly journals A first-principles study of anionic (S) and cationic (V/Nb) doped Sr2Ta2O7 for visible light photocatalysis

RSC Advances ◽  
2017 ◽  
Vol 7 (65) ◽  
pp. 40922-40928 ◽  
Author(s):  
Yuman Peng ◽  
Zuju Ma ◽  
Junjie Hu ◽  
Kechen Wu
Keyword(s):  
Visible Light ◽  
Valence Band ◽  
Conduction Band ◽  
First Principles ◽  
Valence Band Maximum ◽  
Conduction Band Minimum ◽  
Visible Light Photocatalysis ◽  
Band Maximum ◽  
Co Doping ◽  
First Principles Study

In order to utilize the visible light to catalyze water, UV-active Sr2Ta2O7 is engineered via co-doping of S and V/Nb to shift the valence band maximum upward and conduction band minimum downward by approximately 1 eV, respectively.

Structural and Electronic Structure of SnO2 by the First-Principle Study

2012 ◽  
Vol 725 ◽  
pp. 265-268 ◽  
Author(s):  
Minoru Oshima ◽  
Kenji Yoshino
Keyword(s):  
Electronic Structure ◽  
Electronic Properties ◽  
Valence Band ◽  
Conduction Band ◽  
Valence Band Maximum ◽  
First Principle ◽  
Band Maximum ◽  
First Principle Calculations ◽  
Calculation Results ◽  
Good Agreement

We performed first-principle calculations to investigate the effects of F, Cl and Sb impurities on the electronic properties of SnO2. We obtained, firstly, the electronic structure of SnO2, a valence band maximum of SnO2is an O 2p orbital and a conduction band minimum was an antibonding Sn 5s and O 2p orbitals dominantly. Secondly, those impurites doped SnO2was obtained the electronic structure. The F, Cl and Sb impurities as n-type dopants exhibited shallow donors. This calculation results were in good agreement with our prvious experiment that we obtained the low resistivity SnO2.

First-principle calculation of the electronic structure, DOS and effective mass TlInSe2

2017 ◽  
Vol 31 (14) ◽  
pp. 1750155 ◽  
Author(s):  
N. A. Ismayilova ◽  
G. S. Orudzhev ◽  
S. H. Jabarov
Keyword(s):  
Electronic Structure ◽  
Effective Mass ◽  
Valence Band ◽  
Conduction Band ◽  
Density Of States ◽  
Valence Band Maximum ◽  
First Principle ◽  
Band Maximum ◽  
Effective Masses ◽  
Structure Density

The electronic structure, density of states (DOS), effective mass are calculated for tetragonal TlInSe2 from first principle in the framework of density functional theory (DFT). The electronic structure of TlInSe2 has been investigated by Quantum Wise within GGA. The calculated band structure by Hartwigsen–Goedecker–Hutter (HGH) pseudopotentials (psp) shows both the valence band maximum and conduction band minimum located at the T point of the Brillouin zone. Valence band maximum at the T point and the surrounding parts originate mainly from 6s states of univalent Tl ions. Bottom of the conduction band is due to the contribution of 6p-states of Tl and 5s-states of In atoms. Calculated DOS effective mass for holes and electrons are [Formula: see text], [Formula: see text], respectively. Electron effective masses are fairly isotropic, while the hole effective masses show strong anisotropy. The calculated electronic structure, density of states and DOS effective masses of TlInSe2 are in good agreement with existing theoretical and experimental results.

scholarly journals An antibonding valence band maximum enables defect-tolerant and stable GeSe photovoltaics

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Shun-Chang Liu ◽  
Chen-Min Dai ◽  
Yimeng Min ◽  
Yi Hou ◽  
Andrew H. Proppe ◽  
...  
Keyword(s):  
Solar Cells ◽  
Valence Band ◽  
Surface Passivation ◽  
Defect Density ◽  
Perovskite Solar Cells ◽  
Valence Band Maximum ◽  
Ambient Conditions ◽  
Band Maximum ◽  
Point Tracking ◽  
Power Point

AbstractIn lead–halide perovskites, antibonding states at the valence band maximum (VBM)—the result of Pb 6s-I 5p coupling—enable defect-tolerant properties; however, questions surrounding stability, and a reliance on lead, remain challenges for perovskite solar cells. Here, we report that binary GeSe has a perovskite-like antibonding VBM arising from Ge 4s-Se 4p coupling; and that it exhibits similarly shallow bulk defects combined with high stability. We find that the deep defect density in bulk GeSe is ~1012 cm−3. We devise therefore a surface passivation strategy, and find that the resulting GeSe solar cells achieve a certified power conversion efficiency of 5.2%, 3.7 times higher than the best previously-reported GeSe photovoltaics. Unencapsulated devices show no efficiency loss after 12 months of storage in ambient conditions; 1100 hours under maximum power point tracking; a total ultraviolet irradiation dosage of 15 kWh m−2; and 60 thermal cycles from −40 to 85 °C.

Unusual interlayer coupling in layered Cu-based ternary chalcogenides CuMCh2(M=Sb, Bi; Ch=S, Se)

Nanoscale ◽  
2021 ◽  
Author(s):  
Dan-Dong Wang ◽  
Xin-Gao Gong ◽  
Jihui Yang
Keyword(s):  
Electronic Properties ◽  
Conduction Band ◽  
Interlayer Coupling ◽  
Conduction Band Minimum ◽  
Common Mechanism ◽  
Layered Semiconductors ◽  
Band Maximum ◽  
Valance Band Maximum

Interlayer interactions play important roles in manipulating the electronic properties of layered semiconductors. One common mechanism is that the valance band maximum (VBM) and the conduction band minimum (CBM) in...

scholarly journals Synthesis of ZnO doped high valence S element and study of photogenerated charges properties

RSC Advances ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 4422-4427 ◽  
Author(s):  
Lijing Zhang ◽  
Xiufang Zhu ◽  
Zhihui Wang ◽  
Shan Yun ◽  
Tan Guo ◽  
...  
Keyword(s):  
Uniform Distribution ◽  
Valence Band ◽  
Valence Band Maximum ◽  
Band Maximum

The uniform distribution of S dopants elevated the valence band maximum by mixing S 3p with the upper valence band states of ZnO. The valence band maxima of S–ZnO was 0.37 eV higher than that of ZnO.

Valence-band maximum in the layered semiconductor WSe2: Application of constant-energy contour mapping by photoemission

1996 ◽  
Vol 53 (24) ◽  
pp. R16152-R16155 ◽  
Author(s):  
Th. Straub ◽  
K. Fauth ◽  
Th. Finteis ◽  
M. Hengsberger ◽  
R. Claessen ◽  
...  
Keyword(s):  
Valence Band ◽  
Valence Band Maximum ◽  
Layered Semiconductor ◽  
Constant Energy ◽  
Band Maximum ◽  
Contour Mapping ◽  
Energy Contour

Effects of the band offset on interfacial deep levels

1988 ◽  
Vol 3 (1) ◽  
pp. 164-166
Author(s):  
Richard P. Beres ◽  
Roland E. Allen ◽  
John D. Dow
Keyword(s):  
Valence Band ◽  
Energy Levels ◽  
Valence Band Maximum ◽  
Deep Levels ◽  
Band Offset ◽  
Valence Band Offset ◽  
Band Maximum ◽  
Antisite Defects

The energy levels of antisite defects at a GaAs/Ge (110) interface are calculated and shown to be essentially unaltered with respect to the GaAs valence band maximum by different choices of the valence band offset.

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