Red luminescence of Cr in ß-Ga_2O_3 nanowires

Abstract

Red luminescence emission from chromium doped ß-Ga_2O_3 nanowires has been studied by means of photoluminescence (PL) techniques. PL excitation shows several bands in the ultraviolet-visible region. Time decay values, obtained by time resolved PL, at different temperatures fit a three level model with thermal population of the upper level from the middle one. From the results, the origin of the emission is assigned to Cr^3+ ions in the ß-Ga_2O_3 host, and values for the energy level separation and Huang-Rhys factor of the broad^4T_2^(-4)A_2 emission are estimated.