GaAs lower conduction-band minima: Ordering and properties

1976 ◽  
Vol 14 (12) ◽  
pp. 5331-5343 ◽  
Author(s):  
D. E. Aspnes
Keyword(s):  
Conduction Band ◽  
Lower Conduction Band

scholarly journals Searching for promising new perovskite-based photovoltaic absorbers: the importance of electronic dimensionality

2017 ◽  
Vol 4 (2) ◽  
pp. 206-216 ◽  
Author(s):  
Zewen Xiao ◽  
Weiwei Meng ◽  
Jianbo Wang ◽  
David B. Mitzi ◽  
Yanfa Yan
Keyword(s):  
Solar Cells ◽  
Valence Band ◽  
Conduction Band ◽  
Device Performance ◽  
Atomic Orbitals ◽  
Lower Conduction Band

The concept of electronic dimensionality,i.e., the connectivity of the atomic orbitals that comprise the lower conduction band and upper valence band, is introduced to better account for the device performance of the perovskite-based solar cells.

Corrole-sensitized TiO2 solar cells

2006 ◽  
Vol 10 (11) ◽  
pp. 1259-1262 ◽  
Author(s):  
Don Walker ◽  
Shlomit Chappel ◽  
Atif Mahammed ◽  
Bruce S. Brunschwig ◽  
Jay R. Winkler ◽  
...  
Keyword(s):  
Solar Cells ◽  
Excited States ◽  
Conduction Band ◽  
Reducing Power ◽  
Free Base ◽  
Lower Conduction Band

We are investigating the properties of corrole-sensitized TiO 2 solar cells. The TiO 2-adsorbed free base and Ga III corroles display cell efficiencies under AM 1.5 illumination that are about half that of a standard N 3-sensitized cell ( N 3 = cis-bis(4,4'-dicarboxy-2,2'-bipyridine)dithiocyanato ruthenium(II)), while that of the Sn IV-based cell is much lower. The properties of the corrole- TiO 2 solar cells, along with results obtained with electrodes of lower conduction band energies clearly reveal that the reducing power of the singlet excited states of the free base and Ga III corrole, but not of the Sn IV derivative, is sufficiently high for efficient injection into the TiO 2 conduction band.

First-Principles Calculations on the Geometry and Electronic Structure of Rutile TiO2 (110) Surface

2009 ◽  
Vol 79-82 ◽  
pp. 1201-1204
Author(s):  
Hong Bin Su ◽  
Ping Yang ◽  
Jin Biao Wang ◽  
Nan Huang
Keyword(s):  
Oxygen Vacancy ◽  
Conduction Band ◽  
First Principles ◽  
Density Functional ◽  
Surface States ◽  
Atomic Layer ◽  
Left Behind ◽  
Lower Conduction Band ◽  
Super Cell ◽  
Excess Electrons

In this paper, both geometrical and electronic properties of rutile TiO2 (110) surfaces have been investigated using First-Principles Density-Functional calculations with CASTEP code, the model of stoichiometric surface is a (2x1) super-cell which has 12 atomic-layer slabs with the bottom 6 held fixed, the bridging-oxygen vacancy surface has been constructed by removing a neutral bridging oxygen atom from this surface. For the stoichiometric surface, the atom relaxations are: Ti6f (+0.2865Å), Ti5f (-0.1039Å), O3f (+0.2433Å) and Ob (+0.0075Å), we find no reconstruction and no surface states in the band gap, the density of states (DOS) is similar to the bulk except the lower conduction band intensity, in accord with recent experiments. Whereas, as a result of bridging-oxygen vacancy, the atom relaxations exchanged and reconstruction occur. The 2 excess electrons left behind removal of one bridge O atom are localized on the Ti-t2g conduction band orbitals, convert some of the Ti4+ ions into Ti3+ ions and result a compensatory shift in the Fermi level. The band gaps we calculated for stoichiometric surface is similar to the bulk, but its increase can be found for Ob vacancy surface.

scholarly journals Real-time observation of the intravalley spin-flip process in single-layer WS2

2019 ◽  
Vol 205 ◽  
pp. 05012
Author(s):  
Zilong Wang ◽  
Alejandro Molina-Sanchez ◽  
Patrick Altmann ◽  
Davide Sangalli ◽  
Domenico De Fazio ◽  
...  
Keyword(s):  
Real Time ◽  
Conduction Band ◽  
Transient Absorption ◽  
Single Layer ◽  
Transient Absorption Spectroscopy ◽  
Spin Orientation ◽  
Lower Conduction Band ◽  
Spin Polarized ◽  
Time Observation ◽  
Real Time Observation

We use helicity-resolved transient absorption spectroscopy to track intravalley scattering dynamics in monolayer WS2. We find that spin-polarized carriers scatter from upper to lower conduction band by reversing their spin orientation on a sub-ps timescale.

Fine structure in optical transitions from 3d and 4d core levels to the lower conduction band in Ga-V and In-V compounds

1979 ◽  
Vol 31 (2) ◽  
pp. 99-104 ◽  
Author(s):  
D.E. Aspnes ◽  
M. Cardona ◽  
V. Saile ◽  
M. Skibowski ◽  
G. Sprüssel
Keyword(s):  
Fine Structure ◽  
Conduction Band ◽  
Optical Transitions ◽  
Lower Conduction Band

The effect of the mixing of π -and σ -orbitals on the Fermi surface in the l.c.a.o. model for graphite

1956 ◽  
Vol 237 (1208) ◽  
pp. 48-54 ◽  
Keyword(s):  
Conduction Band ◽  
Density Of States ◽  
Unit Cell ◽  
Lower Conduction Band ◽  
Conduction Bands ◽  
Unit Energy ◽  
The Common ◽  
Energy Surfaces ◽  
Secular Determinant ◽  
Group Theoretical Analysis

The common energy of the two principal conduction bands in graphite along the triad axes in k-space is recalculated using an l.c.a.o. model based on sixteen orbitals per unit cell; four 2 s and 2 p ( π and σ ) orbitals centred on each of the four atomic sites in the unit cell. (An earlier calculation took account only of the four 2 p z orbitals.) The results of a group-theoretical analysis are used to show that only 15 of the 136 elements of the resulting 16 x 16 secular determinant are required to compute the doubly degenerate root corresponding to the common energy of the two conduction bands on the triad axes. This energy is found to vary periodically along the triad axes with an amplitude of 0.013 eV. The corresponding overlap of the two conduction bands is about three times larger than the overlap found in the earlier calculation. The resulting correction to the energy surfaces near the triad axes is too small to affect the calculation of the Hall coefficient of graphite for room temperatures based on the earlier calculation, but it is significant at low temperatures. For temperatures below about 50° K and in the absence of electron donors or traps, the conduction region in k-space is confined to the top of the lower conduction band where the density of states per unit energy range is estimated to be 1.1 x 10 -2 √(0.0135 — ϵ ) electronic states per atom per electron-volt, and to the bottom of the upper conduction band where the density of states is found to be 5.8 x 10 -2 √ ϵ . Formulae are given for the shape of the energy surfaces in these regions.

scholarly journals Band alignment of monolayer CaP3, CaAs3, BaAs3 and the role of p–d orbital interactions in the formation of conduction band minima

2021 ◽  
Vol 23 (12) ◽  
pp. 7418-7425
Author(s):  
Magdalena Laurien ◽  
Himanshu Saini ◽  
Oleg Rubel
Keyword(s):  
Electronic Structure ◽  
Conduction Band ◽  
Electron Affinity ◽  
Band Alignment ◽  
Orbital Interactions

We calculate the band alignment of the newly predicted phosphorene-like puckered monolayers with G0W0 according to the electron affinity rule and examine trends in the electronic structure. Our results give guidance for heterojunction design.

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