Structure and opto-electronic properties of MgO nanocrystals calculated by GGA approximation

Abstract

This study uses the CASTEP code and the density functional theory (DFT) to look into the structure, electrical properties, and optical properties of MgO. The generalised gradient approximation (GGA-PW91 approximation) was used to measure both the energy of the band gap and the energy of the exchange-correlation. This computation was done based on the cubic MgO crystal structure, which has a space group of Fm-3m and a 3x3x3 supercell. In structural optimization, the results that are expected for the lattice constant and the bulk modulus elastic constant are very close to known experiments and theories. The anticipated direct band gap of 4.283eV at the G point is in excellent agreement with the results of the tests. Also, the total (DOS) and partial (PDOS) densities of states have been measured, and the results of the absorption coefficient have been looked at in terms of the different energies of the phonons that hit the material.