Ab-initio calculations of the photoelastic constants of the cubic SiC polytype

24th IUPAP Conference on Computational Physics

物理学;计算机科学

Djemia, P.^1 ; Bouamama, Kh^2

LSPM-CNRS, Sorbonne Paris Cité, Université Paris 13, 99 Avenue J.B. Clément, 93430 Villetaneuse, France^1

LOC, Département de Physique, Université Ferhat Abbas, 19000 Sétif, Algeria^2

关键词: Ab initio calculations;    Experimental determination;    Full potential linearized augmented plane waves;    Generalized gradient approximations;    Kohn Sham equations;    Local strain field;    Self-consistent scheme;    Theoretical evaluation;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/454/1/012060/pdf
DOI  :  10.1088/1742-6596/454/1/012060

学科分类：计算机科学（综合）

来源: IOP

【 摘 要 】

Residual defects after growth of semiconductors crystals is a hot issue to be solved for manufacturing new efficient electronic or optic devices. These defects can be conveniently observed using birefringence optical microscopy for extended defects that will create a local strain field which in turn can cause a nominally isotropic optical material to become anisotropic and induce birefringence. In order to perform a quantitative analysis, the knowledge of the photoelastic constants (Pij) of the material that measure the strength of the change of the refractive index under application of strains or stresses is necessary. As an experimental determination of the whole set of constants is not always possible, a theoretical evaluation can be of valuable interest. In this work, we propose ab-initio calculations by the WIEN2k program of the optical properties of the zinc blende silicon carbide polytype with a self-consistent scheme by solving the Kohn-Sham equations using a full potential linearized augmented plane waves (FPLAPW) method in the framework of the density functional theory (DFT) along with the generalized gradient approximation (GGA) pseudo-potentials. A combination of specific compressive and tensile strains is applied to the two atoms unit cell and the tensor containing each specific combination of the Pijconstants is extracted.