First-principles calculations of the electronic and structural properties of GaSb (original) (raw)

Theoretical study of the electronic structure of GaP(110)

Physical review, 1981

A self-consistent pseudopotential approach has been used to calculate the electronic structure of GaP{110jsurface in both ideal and relaxed configurations. Calculations have been performed using the repeated slab method and a local form of the bare ionic pseudopotential. An efficient self-consistent procedure, which allows us to obtain quick convergence and eliminates some difficulties found in previous applications of the method, has been used. Particular care has been devoted to have complete consistency between bulk and slab calculations. Our results for the ideal surface show various surface states, whose distribution and nature are similar to those found in tight-binding calculations. For the geometry of the relaxed surface we assumed a rotation-relaxation model determined by a recent low-energy electron diffraction study. With this geometry our results show that a nonvanishing density of empty surface states, to a large extent due to backbonds, remains in the gap. The orbital composition of these states, as well as of all the other surface features, is detailed, together with the mirror-plane symmetries relevant in the interpretation of angle-resolved photoemission data. Our results are in agreement with the experimental data provided by various different measurements.

An ab initio and density functional study of GaP3− and GaP3

Chemical Physics Letters, 2004

The electronic structure of GaP À 3 and GaP 3 is investigated using density functional theory (B3LYP-DFT), second-order Møller-Plesset perturbation theory (MP2) and the coupled cluster [CCSD(T)] approximation in conjunction with the 6-311+G(2df) one particle basis set. The ground state of GaP À 3 is computed to be 2 A 0 with a C s geometry. Vertical electron detachment energies of the anion are reported and three of the bands observed in the GaP À 3 photodetachment spectrum are reassigned. The ground state of GaP 3 is computed to be 1 A 0-C s with a 1 A 1-C 2v state within 0.3 eV above. The adiabatic electron affinity (AEA) of GaP 3 is calculated to be 1.84 eV at the CCSD(T)//B3LYP and CCSD(T)//MP2 levels.

Self Consistent Calculations of Electronic Properties of Systems with an Energy or a Band Gap

2012

Unquestionably, the BZW-EF method i rofoundtr t o"?lL"tit" as (a) it provides accurare, electronic, structurar, tanspo( opucal,-;d ryF; p-p€xtio of semiconductors, including band gaps, and (b) it ushers in an era ofab-initio, r"ir-"iorirt""t, and accurate predictions of properties of novel materials-Hence, Bzw-EF caiculations Ln inform and guirle the design and fabrication of deYices based on finite or crystalline materials witfi energr or band gapg respectively.

AB-INITIO CALCULATIONS OF ELECTRONIC PROPERTIES OF InP AND GaP

International Journal of Modern Physics B, 2013

We present results from ab-initio, self-consistent local density approximation (LDA) calculations of electronic and related properties of zinc blende indium phosphide (InP) and gallium phosphide (GaP). We employed a LDA potential and implemented the linear combination of atomic orbitals (LCAO) formalism. This implementation followed the Bagayoko, Zhao and Williams (BZW) method, as enhanced by Ekuma and Franklin (BZW-EF). This method searches for the optimal basis set that yields the minima of the occupied energies. This search entails increases of the size of the basis set and the related modifications of angular symmetry and of radial orbitals. Our calculated, direct band gap of 1.398 eV (1.40 eV), at the Γ point, is in excellent agreement with experimental values, for InP, and our preliminary result for the indirect gap of GaP is 2.135 eV, from the Γ to X high symmetry points. We have also calculated electron and hole effective masses for both InP and GaP. These calculated properties also agree with experimental findings. We conclude that the BZW-EF method could be employed in calculations of electronic properties of high-Tc superconducting materials to explain their complex properties.

An ab initio study of ground state, electronic and thermodynamical properties of GaP and Ga2P

Journal of Thermal Analysis and Calorimetry, 2012

In the present paper, we report an ab initio calculation of the ground state, electronic and thermodynamical properties like constant volume lattice specific heat, vibrational energy, internal energy, and entropy for GaP and Ga 2 P is presented. These properties are obtained after calculating the phonon spectrum over the entire Brillouin zone. The calculations were performed using the ABINIT program package, which is based on density functional theory (DFT) method and the use of pseudopotentials and plane wave expansion. Difference in the ground state properties such as electronic structure and thermodynamical properties are discussed. The thermodynamical properties follow the expected trend. There is a good agreement between present theoretical and limited available experimental data in the case of ground state such as lattice constant and bulk modulus and electronic properties. With the increase of Ga atoms in the unit cell the semiconducting nature of Ga 2 P turns to metallic. There is a noticeable difference in the thermodynamical properties in the case of both gallium compounds.

First-principles calculation of Ga-based semiconductors

Physical Review B, 1995

The physical properties of the III-V semiconducting compounds, GaP, GaAs, and GaSb, have been calculated by employing a scalar relativistic version of the first-principles full-potential self-consistent linearized-muon-tin-orbital method. The calculated values of the lattice parameters of the compounds are reproduced well within 2.6' of the measured values. The computed dispersion curves and the electronic density of states are in excellent agreement with the available photoemission data for all the compounds. The predicted bulk modulus and the elastic constants are in close agreement with the experimental data where available. The frequencies of the frozen phonons at symmetry points are in good agreement with the available measured data.

Accurate determination of band gaps within density functional formalism

In this paper, we report an adaptation of the Harbola-Sahni (HS) exchange potential to the tight-binding linear muffin-tin orbital (TB-LMTO) method to determine band gaps (BGs) of solids accurately. We show that the electrostatic basis of derivation of the Harbola-Sahni potential allows this nonvariational approach to improve substantially over local-density approximation derived BGs, bringing them very close to experimental values. That the accuracy of the HS potential is directly responsible for the determination of correct BGs is demonstrated by performing similar calculations with an accurate model potential that too leads to BGs close to their experimental values. Moreover, ground-state properties like equilibrium lattice parameters and bulk moduli (BM) for various semiconductors like C, Si, AlN, AlP, BP, and 3C-SiC calculated with the HS approach are in close agreement with the experiments. The clear physical interpretation of HS potential leads us to suggest exploring its use for calculating various properties of solids.