Ultraviolet-green photoluminescence of β-Ga2O3 films deposited on MgAl6O10 (100) substrate

beta-Ga2O3 films were grown on double-side polished MgAl6O10 (100) substrate by metal organic chemical vapor deposition (MOCVD) at 600, 650 and 700 degrees C. The refractive index dispersive behaviors of Ga2O3 films have the typical shape of the normal dispersion curve. Photoluminescence (PL) spectra measured at room temperature revealed that all the films exhibited intense ultraviolet (UV)-green emission from 300 to 650 nm. A minor deep UV emission around 275 nm (similar to 4.51 eV) Was observed for the sample prepared at 700 degrees C. The intensity of the emission increased markedly when measured at low temperature. The corresponding PL mechanisms were discussed in detail and a schematic diagram was proposed. (C) 2013 Elsevier B.V. All rights reserved.