Using cluster studies to approach the electronic structure of bulk water: Reassessing the vacuum level, conduction band edge, and band gap of water

1997 ◽  
Vol 107 (16) ◽  
pp. 6023-6031 ◽  
Author(s):  
James V. Coe ◽  
Alan D. Earhart ◽  
Michael H. Cohen ◽  
Gerald J. Hoffman ◽  
Harry W. Sarkas ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Band Gap ◽  
Conduction Band ◽  
Bulk Water ◽  
Band Edge ◽  
Conduction Band Edge ◽  
Vacuum Level

Electronic Structure and Surface Properties of SrBi2Ta2O9 and Related Oxides

1997 ◽  
Vol 493 ◽  
Author(s):  
J Robertson ◽  
C W Chen
Keyword(s):  
Electronic Structure ◽  
Band Gap ◽  
Conduction Band ◽  
Tight Binding ◽  
Schottky Barriers ◽  
Band Edge ◽  
Conduction Band Edge ◽  
Edge States ◽  
Tight Binding Method ◽  
S States

ABSTRACTThe electronic structure of SrBi2Ta2O9 and related oxides such as SrBi2Nb2O9, Bi2WO6 and Bi3Ti4O12 have been calculated by the tight-binding method. In each case, the band gap is about 4.1 eV and the band edge states occur on the Bi-O layers and consist of mixed O p/Bi s states at the top of the valence band and Bi p states at the bottom of the conduction band. The main difference between the compounds is that Nb 5d and Ti 4d states in the Nb and Ti compounds lie lower than the Ta 6d states in the conduction band. The surface pinning levels are found to pin Schottky barriers 0.8 eV below the conduction band edge.

scholarly journals Phase transition-induced band edge engineering of BiVO4 to split pure water under visible light

2015 ◽  
Vol 112 (45) ◽  
pp. 13774-13778 ◽  
Author(s):  
Won Jun Jo ◽  
Hyun Joon Kang ◽  
Ki-Jeong Kong ◽  
Yun Seog Lee ◽  
Hunmin Park ◽  
...  
Keyword(s):  
Phase Transition ◽  
Visible Light ◽  
Band Gap ◽  
Conduction Band ◽  
Density Functional ◽  
Density Functional Theory Calculation ◽  
Pure Water ◽  
Volume Growth ◽  
Band Edge ◽  
Conduction Band Edge

Through phase transition-induced band edge engineering by dual doping with In and Mo, a new greenish BiVO4 (Bi1-XInXV1-XMoXO4) is developed that has a larger band gap energy than the usual yellow scheelite monoclinic BiVO4 as well as a higher (more negative) conduction band than H+/H2 potential [0 VRHE (reversible hydrogen electrode) at pH 7]. Hence, it can extract H2 from pure water by visible light-driven overall water splitting without using any sacrificial reagents. The density functional theory calculation indicates that In3+/Mo6+ dual doping triggers partial phase transformation from pure monoclinic BiVO4 to a mixture of monoclinic BiVO4 and tetragonal BiVO4, which sequentially leads to unit cell volume growth, compressive lattice strain increase, conduction band edge uplift, and band gap widening.

scholarly journals Al Doped ZnO Thermoelectrics Determined from Electronic Structure

2020 ◽  
Author(s):  
Rundong Wan ◽  
Quanwei Jiang ◽  
Zhengfu Zhang ◽  
Sharon Kao-Walter ◽  
Ying Lei ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Sample Preparation ◽  
Conduction Band ◽  
Carrier Mobility ◽  
Transport Theory ◽  
Band Edge ◽  
Conduction Band Edge ◽  
Boltzmann Transport ◽  
Boltzmann Transport Theory ◽  
Doped Zno

Abstract For the aluminium doped wurtzite ZnO, comparing the Boltzmann transport theory calculated results and existing experiments, we acquire a few properties that are inaccessible otherwise. We find that the doping makes the samples metallic as the shifted Fermi levels are above the conduction band edge. We further find that the contradictory conclusions from two experiments with similar formula can be attributed to the quite disparate carrier concentrations and carrier mobility and the carrier mobility strong relates to the sample preparation.

First principles study of electronic structures of dopants in Mg2Si

2011 ◽  
Vol 1329 ◽  
Author(s):  
K. Xiong ◽  
S. Sobhani ◽  
R. P. Gupta ◽  
W. Wang ◽  
B. E. Gnade ◽  
...  
Keyword(s):  
Band Gap ◽  
Valence Band ◽  
Conduction Band ◽  
Density Of States ◽  
First Principles ◽  
Band Edge ◽  
Conduction Band Edge ◽  
Hybrid Functional ◽  
Thermoelectric Efficiency ◽  
The Impact

ABSTRACTWe investigate the impact of various dopants (Na, Ag, Cd, Zn, Al, Ga, In, Tl, Ge, and Sn) on the electronic structure of Mg2Si by first principles calculations using a hybrid functional that does not need a band gap correction. We find that for Na and Ge in Mg2Si, the impurity-induced states do not affect the density of states at both edges of the valence band and the conduction band. Ag- and Sn affect slightly the density of states at the valence band edge, while Cd and Zn affect slightly the density of state at the conduction band edge. Al and In could modify significantly the density of states at the conduction band edge. Ga introduces states just at the bottom of the conduction band. Tl introduces states in the band gap. This study provides useful information on optimizing the thermoelectric efficiency of Mg2Si.

Electronic properties and band offsets in InP(1−x−y)BixNy

2019 ◽  
Vol 33 (06) ◽  
pp. 1950058 ◽  
Author(s):  
Kailin Wang ◽  
Dan Liang ◽  
Yang Li ◽  
Shumin Wang ◽  
Ming Lei ◽  
...  
Keyword(s):  
Band Gap ◽  
Valence Band ◽  
Conduction Band ◽  
Band Edge ◽  
Conduction Band Edge ◽  
Hamiltonian Matrix ◽  
Band Offset ◽  
Electronic Band ◽  
Strong Control ◽  
Band Anticrossing

Electronic band structures of [Formula: see text] have been theoretically studied by using Conduction Band Anticrossing (CBAC) model and Valence Band Anticrossing model (VBAC) in conjugation with [Formula: see text] method. This mathematical model’s manifestation is a 16 band Hamiltonian matrix. Our results reveal that the addition of Bi and N to InP causes substantial reduction of band gap, and the conduction band offset is greater than valence band offset. It can provide better electronic confinement and improve the temperature-insensitive characteristics for optoelectronic devices. Material compositions and band gap under various strain conditions have also been added in our calculation. By adjusting the concentration of Bi and N, we obtained a strong control of conduction band edge and valence band edge, which increases the flexibility of design InPBiN/InP structures.

scholarly journals Conduction Band Edge Energy Profile Probed by Hall Offset Voltage in InGaZnO Thin Films

Micromachines ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 822
Author(s):  
Hyo-Jun Joo ◽  
Dae-Hwan Kim ◽  
Hyun-Seok Cha ◽  
Sang-Hun Song
Keyword(s):  
Magnetic Field ◽  
Electron Density ◽  
Conduction Band ◽  
Electron System ◽  
Band Edge ◽  
Conduction Band Edge ◽  
Offset Voltage ◽  
Three Samples ◽  
Dimensional Electron System ◽  
Longitudinal Distance

We measured and analyzed the Hall offset voltages in InGaZnO thin-film transistors. The Hall offset voltages were found to decrease monotonously as the electron densities increased. We attributed the magnitude of the offset voltage to the misalignment in the longitudinal distance between the probing points and the electron density to Fermi energy of the two-dimensional electron system, which was verified by the coincidence of the Hall voltage with the perpendicular magnetic field in the tilted magnetic field. From these results, we deduced the combined conduction band edge energy profiles from the Hall offset voltages with the electron density variations for three samples with different threshold voltages. The extracted combined conduction band edge varied by a few tens of meV over a longitudinal distance of a few tenths of µm. This result is in good agreement with the value obtained from the analysis of percolation conduction.

Size-Dependent Valence and Conduction Band-Edge Energies of Semiconductor Nanocrystals

ACS Nano ◽  
2011 ◽  
Vol 5 (7) ◽  
pp. 5888-5902 ◽  
Author(s):  
Jacek Jasieniak ◽  
Marco Califano ◽  
Scott E. Watkins
Keyword(s):  
Conduction Band ◽  
Semiconductor Nanocrystals ◽  
Band Edge ◽  
Conduction Band Edge ◽  
Size Dependent
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