Atomistic Calculations of Dopant Binding Energies in ZnGeP2

1997 ◽  
Vol 484 ◽  
Author(s):  
Ravindra Pandey ◽  
Melvin C. Ohmer ◽  
A. Costales ◽  
J. M. Recio
Keyword(s):  
Experimental Data ◽  
Band Gap ◽  
Interatomic Potential ◽  
Host Lattice ◽  
Binding Energies ◽  
First Principle ◽  
Atomistic Model ◽  
Group Iii ◽  
Atomistic Calculations

AbstractAtomistic model has been applied to study various cation dopants, namely Cu, Ag, B, Al, Ga and In in ZnGeP2. The pairwise interatomic potential terms representing the interaction of dopants with the host lattice ions are derived using first principle methods. Defect calculations based on Mott-Littleton methodology predict small binding energies for Cu and Ag substituting Zn in the lattice which are in agreement with the available experimental data. The group III dopants (i.e. B, Al, Ga and In) at the Ge site are predicted to have large binding energies for a hole except B which shows a distinct behavior. This may be due to large mismatch in atomic sizes of B and Ge. At the Zn site, the calculated binding energies of the group III dopants place donor levels in the middle of the band gap.

Modeling of the Properties of Dopants in the NLO Semiconductor CdGeAs2

1999 ◽  
Vol 607 ◽  
Author(s):  
Ravindra Pandey ◽  
Melvin C. Ohmer ◽  
A. Costales ◽  
J. M. Recio
Keyword(s):  
Experimental Data ◽  
Band Gap ◽  
Shell Model ◽  
Interatomic Potential ◽  
Host Lattice ◽  
Binding Energies ◽  
First Principle ◽  
Group Iii ◽  
Model Study

AbstractThe results of a shell-model study on CdGeAs2 doped with Cu, Ag, B, Al, Ga, and In are presented here. The pairwise interatomic potential terms representing the interaction of dopants with the host lattice ions are derived using first principle methods while empirical fitting methods are used for the host-lattice potentials. Defect calculations based on Mott-Littleton methodology predict small binding energies for Cu and Ag substituting Cd in the lattice which are in agreement with the available experimental data. The group III dopants (i.e. B, Al, Ga and In) at the Ge site are predicted to have large binding energies for a hole placing acceptor levels in the middle of the band gap.

First principle investigation of stuctural, electronic, and thermoelectric properties of Ga1-xInxP (x = 0.0 to 1.0) alloys

2022 ◽  
Author(s):  
Abeer AlObaid
Keyword(s):  
Electrical Conductivity ◽  
Band Gap ◽  
Thermoelectric Properties ◽  
Power Factor ◽  
Figure Of Merit ◽  
First Principle ◽  
Group Iii V Semiconductors ◽  
Thermoelectric Devices ◽  
Group Iii ◽  
Maximum Value

Abstract Group III-V semiconductors are extensively studied for various technological applications. Different properties of Ga1-xInxP such as electronic, optical, elastic, thermal and mechanical, etc. were studied under different concentrations. However, there is no evident for thermoelectric performance of Ga1-xInxP (x = 0.0, 0.25, 0.50, 0.75 and 1.0). In the present study, we have calculated the structural, electronic and thermoelectric behavior of Ga1-xInxP by utilizing the WIEN2K package. The InP show indirect semiconductor nature of band gap of 2.1 eV. By adding the concentration of In, the band gap nature shifts from indirect to direct with a decrease in the band gap. For thermoelectric properties, Seebeck, thermal and electrical conductivity, power factor and figure of merit ZT are investigated through the BoltzTraP code. Our study reveals that Ga1-xInxP has a maximum value of ZT=0.79 at x=1, provide an opportunity for developing good thermoelectric devices.

First-Principle Study of the Structural, Electronic, and Optical Properties of Cubic InNxP1–x Ternary Alloys under Hydrostatic Pressure

2016 ◽  
Vol 71 (9) ◽  
pp. 783-796 ◽  
Author(s):  
I. Hattabi ◽  
A. Abdiche ◽  
R. Moussa ◽  
R. Riane ◽  
K. Hadji ◽  
...  
Keyword(s):  
Experimental Data ◽  
Optical Properties ◽  
Hydrostatic Pressure ◽  
Bulk Modulus ◽  
Band Gap ◽  
Lattice Constant ◽  
First Principle ◽  
Electronic Band ◽  
Electronic And Optical Properties ◽  
Good Agreement

AbstractIn this article, we present results of the first-principle study of the structural, electronic, and optical properties of the InN, InP binary compounds and their related ternary alloy InNxP1–x in the zinc-blend (ZB) phase within a nonrelativistic full potential linearised augmented plan wave (FP-LAPW) method using Wien2k code based on the density functional theory (DFT). Different approximations of exchange–correlation energy were used for the calculation of the lattice constant, bulk modulus, and first-order pressure derivative of the bulk modulus. Whereas the lattice constant decreases with increasing nitride composition x. Our results present a good agreement with theoretical and experimental data. The electronic band structures calculated using Tran-Blaha-modified Becke–Johnson (TB-mBJ) approach present a direct band gap semiconductor character for InNxP1–x compounds at different x values. The electronic properties were also calculated under hydrostatic pressure for (P=0.00, 5.00, 10.0, 15.0, 20.0, 25.0 GPa) where it is found that the InP compound change from direct to indirect band gap at the pressure P≥7.80 GPa. Furthermore, the pressure effect on the dielectric function and the refractive index was carried out. Results obtained in our calculations present a good agreement with available theoretical reports and experimental data.

scholarly journals Properties of Novel Non-Silicon Materials for Photovoltaic Applications: A First-Principle Insight

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2006 ◽  
Author(s):  
Murugesan Rasukkannu ◽  
Dhayalan Velauthapillai ◽  
Federico Bianchini ◽  
Ponniah Vajeeston
Keyword(s):  
Band Gap ◽  
Density Functional ◽  
Crystalline Silicon ◽  
Visible Region ◽  
Initial Population ◽  
First Principle ◽  
Direct Band Gap ◽  
Depth Analysis ◽  
Photovoltaic Applications ◽  
Direct Band

Due to the low absorption coefficients of crystalline silicon-based solar cells, researchers have focused on non-silicon semiconductors with direct band gaps for the development of novel photovoltaic devices. In this study, we use density functional theory to model the electronic structure of a large database of candidates to identify materials with ideal properties for photovoltaic applications. The first screening is operated at the GGA level to select only materials with a sufficiently small direct band gap. We extracted twenty-seven candidates from an initial population of thousands, exhibiting GGA band gap in the range 0.5–1 eV. More accurate calculations using a hybrid functional were performed on this subset. Based on this, we present a detailed first-principle investigation of the four optimal compounds, namely, TlBiS2, Ba3BiN, Ag2BaS2, and ZrSO. The direct band gap of these materials is between 1.1 and 2.26 eV. In the visible region, the absorption peaks that appear in the optical spectra for these compounds indicate high absorption intensity. Furthermore, we have investigated the structural and mechanical stability of these compounds and calculated electron effective masses. Based on in-depth analysis, we have identified TlBiS2, Ba3BiN, Ag2BaS2, and ZrSO as very promising candidates for photovoltaic applications.

A POSSIBLE FIRST PRINCIPLE ARGUMENTS ON THE SYMMETRY OF SUPERCONDUTING GAP PARAMETER

1999 ◽  
Vol 13 (29n31) ◽  
pp. 3440-3442 ◽  
Author(s):  
CHANGDE GONG
Keyword(s):  
Experimental Data ◽  
Theoretical Prediction ◽  
Cuprate Superconductors ◽  
Superconducting Gap ◽  
First Principle ◽  
General Physical ◽  
Gap Parameter

The symmetry of superconducting gap parameter in high-Tc cuprate superconductors has been studied based on general physical considerations. The disagreement between theoretical prediction and experimental data is discussed.

scholarly journals Температурная зависимость ширины запрещенной зоны монокристаллов MnAgIn-=SUB=-7-=/SUB=-S-=SUB=-12-=/SUB=-

2019 ◽  
Vol 53 (12) ◽  
pp. 1621
Author(s):  
И.В. Боднарь ◽  
Б.Т. Чан ◽  
В.Н. Павловский ◽  
И.Е. Свитенков ◽  
Г.П. Яблонский
Keyword(s):  
Experimental Data ◽  
Temperature Dependence ◽  
Band Gap ◽  
Single Crystals ◽  
Spinel Structure ◽  
Semiconductor Materials ◽  
Transmittance Spectra ◽  
Temperature Range

AbstractMnAgIn_7S_12 single crystals 16 mm in diameter and ~40 mm in length are grown by planar crystallization of the melt. It is shown that the material grown crystallizes with the formation of the cubic spinel structure. From the transmittance spectra recorded in the region of fundamental absorption in the temperature range 10–320 K, the band gap E _ g of the single crystals and its temperature dependence are determined. The dependence has a shape typical of most semiconductor materials: as the temperature is lowered, the band gap E _ g increases. A calculation is carried out, and it is shown that the calculated values are in agreement with the experimental data.

Incomplete Solubility in Nitride Alloys

1996 ◽  
Vol 449 ◽  
Author(s):  
I. H. Ho ◽  
G.B. Stringfellow
Keyword(s):  
Experimental Data ◽  
Nearest Neighbor ◽  
Solubility Limit ◽  
Lattice Parameter ◽  
Miscibility Gap ◽  
Recent Experimental Data ◽  
Virtual Crystal Approximation ◽  
Group V ◽  
Group Iii ◽  
Nitride Alloys

ABSTRACTA model based on the valence-force-field (VFF) model has been developed specifically for the calculation of the irascibility gaps in III-V nitride alloys. In the dilute limit, this model allows the relaxation of the atoms on both sublattices. It was found that the energy due to bond stretching and bond bending was lowered and the solubility limit was increased substantially when both sublattices were allowed to relax to distances as large as the sixth nearest neighbor positions. Using this model, the equilibrium mole fraction of N in GaP was calculated to be 6×l0−7 at 700°C. This is slightly higher than the calculated results from the semi-empirical delta lattice parameter (DLP) model. Both the temperature dependence and the absolute values of the calculated solubility agree closely with the experimental data. The solubility is more than three orders of magnitude larger than the result obtained using the VFF model with the group V atom positions given by the virtual crystal approximation, i.e., with relaxation of only the first neighbor bonds. Other nitride systems, such as GaAsN, AlPN, AlAsN, InPN, and InAsN were investigated as well. The equilibrium mole fractions of nitrogen in InP and InAs are the highest, which agrees well with recent experimental data where high N concentrations have been produced in InAsN alloys. Calculations were also performed for the alloy systems with mixing on the group III sublattice that are so important for device applications. Allowing relaxation to the 3rd nearest neighbor gives an In solubility in GaN at 800°C of less than 6%. Again, this is in agreement with the results of the DLP model calculation. This result may partially explain the difficulties experienced with the growth of these alloys. Indeed, evidence of solid immiscibility has recently been reported. A significant miscibility gap was also calculated for the AlInN system, but the AlGaN system is completely miscible.

Modification on TiO2-a Photosensitive Material

2013 ◽  
Vol 579-580 ◽  
pp. 148-152
Author(s):  
Miao Sun ◽  
Yong Hu ◽  
Hua Guo
Keyword(s):  
Density Functional Theory ◽  
Band Gap ◽  
Light Absorption ◽  
Potential Application ◽  
Density Functional ◽  
First Principle ◽  
Functional Theory ◽  
Photosensitive Material ◽  
The Past ◽  
Light Area

TiO2, as photosensitive materials, has attracted much attention owing to its potential application in the solution of environmental pollution during the past decades. Four doped TiO2systems were constructed and studied by using the first principle based Density Functional Theory .The results indicate that P-doped and N-doped TiO2all have better light absorption in the visible light area than pristine TiO2although the band gap of N-doped system reduced less. However, the band gap of F-doped and Cl-doped TiO2increase a little, which causing the absorption to decrease. We suggest from the results that the P atom and N atom are valuable in the modification of TiO2.

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