Refractive Index of BAs<sub>1-x</sub>P<sub>x</sub> Semiconductors

Abstract

Ternary alloys of group III-V semiconductors have important applications in fabrication of electro-optical devices. Their refractive index and related optical properties are of attractive interest in theoretical and experimental study. According to the Philips scale of iconicity, BP (fi =0.006) and BAs (fi =0.002) are the most covalent of the III-V semiconductors and there are interesting consequences of this property. We present a theoretical procedure for the study of refractive index of ternary alloy BAs1-xPx. The calculations are based on the pseudopotential formalism in which local potential coupled with the virtual crystal approximation (VCA) is applied to evaluate refractive index for the entire range of the alloy composition x of the ternary alloy BAs1-xPx. To incorporate screening effect, Nagy’s local field correction function has been employed. The screening functions of Hartree, Taylor, Ichimaru et al., Farid et al. and Sarkar et al. are also integrated for comparative study. Our results for parent compounds are compared to experiment and other available such theoretical findings and showed relatively good agreement. During present theoretical study it is concluded that refractive index fairly depends on the selection of the local field correction function.