Electronic, optical spectra and the distribution of Mn impurities in GaN and group-IV semiconductors

Abstract

By use of the first-principles density-functional approach, pair impurity configurations, magnetic and optical properties of Mn-doped GaN, Ge and Si were calculated. From the total energies calculated for various possible distributions, substitutional Mn atoms in GaN were found to prefer the dimer configuration with the shortest Mn–Mn distances, while in Ge:Mn and Si:Mn the uniform distribution of Mn atoms is more stable. The most remarkable changes in optical spectra occur in the infrared region due to the optical interband transitions between impurity-induced states.