Non-local exchange correlation functionals impact on the structural, electronic and optical properties of III-V arsenides
AuthorsAnua, N. Najwa
Saeed, Mohammad Alam
Ul Haq, Bakhtiar
KAUST DepartmentPhysical Sciences and Engineering (PSE) Division
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AbstractExchange correlation (XC) energy functionals play a vital role in the efficiency of density functional theory (DFT) calculations, more soundly in the calculation of fundamental electronic energy bandgap. In the present DFT study of III-arsenides, we investigate the implications of XC-energy functional and corresponding potential on the structural, electronic and optical properties of XAs (X = B, Al, Ga, In). Firstly we report and discuss the optimized structural lattice parameters and the band gap calculations performed within different non-local XC functionals as implemented in the DFT-packages: WIEN2k, CASTEP and SIESTA. These packages are representative of the available code in ab initio studies. We employed the LDA, GGA-PBE, GGA-WC and mBJ-LDA using WIEN2k. In CASTEP, we employed the hybrid functional, sX-LDA. Furthermore LDA, GGA-PBE and meta-GGA were employed using SIESTA code. Our results point to GGA-WC as a more appropriate approximation for the calculations of structural parameters. However our electronic bandstructure calculations at the level of mBJ-LDA potential show considerable improvements over the other XC functionals, even the sX-LDA hybrid functional. We report also the optical properties within mBJ potential, which show a nice agreement with the experimental measurements in addition to other theoretical results. © 2013 IOP Publishing Ltd.
SponsorsAuthors would like to thank the Ministry of Higher Education (MOHE) Malaysia/Universiti Teknologi Malaysia (UTM) for financial support for this research work through grant nos R.J130000.7726.4D034; Q.J130000.2526.02H89; R.J130000.7826.4F113. Moreover, SGS wish to thank the research computing service (KAUST-IT) for access to CASTEP code.