Optical properties of multilayer (III–V semiconductors) thin films within the framework of DFT + characteristic matrix

We present a new model of calculations based on DFT and Abeles matrix theory to understand the optical properties of semiconductor thin films which form the active layers in many optoelectronic applications. We show how optical quantities such as refractive index, extinction coefficient and band gap can change the optical representations of thin films. In this study two main types of calculations are carried out. The first is the calculation of the dielectric functions within the density functional theory framework (DFT). The second is the calculation of the optical transmittance, absorbance and reflection of monolayer and multilayer thin films within the Abeles matrix theory. The output of this combination (DFT + characteristic matrix) is very helpful and the effect of many parameters like thickness, incidence angle and light polarization on optical properties of multilayer systems can be easily investigated.