Extant ionic charge theory for bond orbital model based on the tight-binding method: A semi-empirical model applied to wide-bandgap II-VI and III-V semiconductors

Abstract

In order to enhance the viability of this review for that issue, I suggest adding this to the beginning of the Abstract: "Binary semiconductors with II-VI and III-V composition, owing to their direct and typically rather wide gap, are technologically important materials. The recent successful fabrication of the blue-green laser diode based on these compounds has renewed interest in their physical properties In this review the correlations are presented for the bond polarity (αp), hybrid covalent energy (V2) and elastic constants (Cij) and may be represented by linear equations. These are simple function of product of ionic charges of cation and anion (Z1Z2) and nearest neighbour distance (d in Å). On the basis of this result a bond orbital calculations based on the tight-binding method is used to estimate the hybrid covalency (αc), hybrid polar energy (V3), effective charge, transverse effective charge (eT), Kleinman׳s internal displacement parameter (ζ), bulk modulus (B), shear constant (C11−C12)/2, shear modulus (G), Young׳s modulus (Y), bond stretching force constants (α), bond bending force constants (β) of a number of ordered ANB8−N semiconductors. The proposed expressions can be applied to a broad selection of covalent materials and their predictions are in good agreement with the experimental data and those from ab initio calculations.