Luminescence of Cr-doped β-Ga2O3 thin films

The results of investigation of optical excitation, photoluminescence (PL) and cathodoluminescence (CL) spectra in Cr-doped β-Ga2O3 thin films are presented. The broad bands due to the generation of electron-hole pairs and transitions from the 4А2 ground level to the 4Т1 and 4Т2 excited states in Cr3+ ions are observed in the photoexcitation spectra. The R-lines and phonon repetitions of R-lines are observed on the luminescence spectra against the background of a broad structureless band with a maximum around 700 nm, caused by the 4T2 – 4A2 transitions in Cr3+ ions. The crystal field force Dq was determined and the Stokes and anti-Stokes repetitions of R-lines were interpreted.