Computational Investigation of Electronic and Optical Properties of Si, Ge and Si1-xGex Alloys Using the FP-LMTO Method Augmented by a Plane-Wave Basis

An investigation into the structural, electronic and optical properties of Si, Ge, and Si1-xGex for different compositions was conducted using first-principles calculations based on density functional theory (DFT). The total energies were calculated within the full -potential linear muffin-tin orbital (FP-LMTO) method augmented by a plane-wave basis (PLW), implemented in Lmtar code. The effects of the approximations to the exchange-correlation energy were treated by the local density approximation (LDA). From our simulation results, it is found that the theoretical ground-state parameters, the band structure, the density of states (DOS), the chemical bonding and the optical properties agree well with the experiment and other theoretical calculations. The accuracies found from the present calculations allow us to describe the properties of the electronic as well as the optoelectronic devices based on the Si1-xGex alloy.