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CPCQ 2015, 31 Mars - 02 Avril 2015
Theoretical investigation of optical properties of zinc blende III-Antimony materials Moufdi Hadjaba*, Smail Berrahb, Mohamed Issam Zianec, Hamza Bennacerd, Hamza Abidc
a Thin films and Application unit (UDCMA),Setif -Welding and NDT Research Center (CSC),Cheraga, Algiers, Algeria.
b Department of Electronic, faculty of technology, University of A/Rahmen Mira, Bejaia, Algeria.
cApplied Materials Laboratory, Research Center, University Djillali Liabes, 22000 Sidi Bel Abbes, Algeria.
d Department of Electronic, faculty of technology, University of Msila, BP 166, 28000 Msila, Algeria.
* moufdi84@yahoo.fr
Abstract
A first-principles calculations have been performed, using the Full Potential Linearized Augmented Plane Wave (FP- LAPW) calculations based on Density Functional Theory (DFT) method as implemented in Wien2k code [1], to evaluate the optical properties of III-Antimony binary compounds AlSb, GaSb and InSb, using the new semi-local modified Becke–
Johnson potential (TB-mBJ) [2] developed by Tran and Blaha. The real and the imaginary parts of the dielectric function, absorption coefficient, reflectivity and optical conductivity versus photon energy were presented to discuss optical properties of III-Sb. The results obtained were compared with experimental data and other computational works, suggesting our compounds as suitable materials for optoelectronic device applications.
Keywords: FP-LAPW, DFT, mBJ-BT, Optical parameters.
1. Introduction
Semiconductor materials are essential for modern electronics, many conductors based devices (such as computer and mobile phones) have become an inseparable part of everyday life. The best known and most widely used semiconductor material is silicon but many others have important applications as well [3]. Antimonides are semiconductors of great physical interests, InSb, is particularly interesting for both band structure theory and infrared optoelectronic device applications.
GaSb has been mostly studied for its fundamental properties than for technological applications, AlSb is an indirect edge semiconductor, which is particularly interesting for GaAlSb based optoelectronic devices in the 1,3–1,6 mm wavelength range and for the solar energy conversion [4].
2. Computational Details
Total energy calculations of the optical properties of zinc-blende binary AlSb, GaAs and InSb were performed using the full potential linearized augmented plane wave (FPLAPW). In this method, the unit cell is partitioned into non-overlapping muffin-tin spheres around the atomic sites, and an interstitial region. Among these two types of regions different basis sets are used, the Kohn-Sham equation which is based on the density functional theory (DFT) [5–6] is solved in a self consistent scheme.
Fig. 1: Crystal structure of III-Sb (primitive cell).
2 For the exchange-correlation potential, the local density approximation (LDA) [7-8], the revised Perdew-Burke-Ernzerhof generalized gradient approximation (GGA-PBEsol) [9], were applied only in calculating structural properties. The Engel-Vosko GGA (EV-GGA) formalism [10] and the modified Becke–Johnson (mBJ) approach [2] were used to calculate the electronic and optical properties.
To obtain energy eigenvalues convergence, the plane wave expansion with an RMT×KMAX was equal to 9, where RMT is the smallest radii of the muffin-tin spheres and KMAX is the cut-off for the wave function basis. The RMT values (muffin-tin radii) were taken to be 2.2 atomic unit (a.u) for Al, Ga, In, and 2.5 for Sb, for AlSb, GaSb and InSb binary compounds. The spherical harmonics inside non-overlapping muffin tin (MT) spheres surrounding the atoms are expanded up to lmax=10, The Fou- rier-expanded charge density was truncated at Gmax=12 (a.u)-1. The irreducible wedge of the Brillouin zone was described by a mesh of 47 special k-points (grid of 10×10×10 meshes, equivalent to 1000 K- points in the entire BZ) for binary compounds. In case of optical calculations, we used denser meshes of 492 k-points, Self-consistent calculations are considered to have converged when the total energy of the system is stable within less than 10-5 Ryd.
3. Conclusion
The purpose of this work is to study the optical properties of the cubic Zinc-blende AlSb, GaSb and InSb, using the numerical simulation method based on ab-initio calculations. The present calculations gives a new results concerning optical properties of the binaries compounds.These materials presents a particular interest in the optoelectronic devices area and solar cell
References
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