Deep ultraviolet photoconductive and near-infrared luminescence properties of Er3+-doped β-Ga2O3 thin films

Highly oriented (2¯01) Er3+-doped β-Ga2O3 (Er:Ga2O3) thin films with different doping concentrations were grown on (0001) sapphire substrates using radio frequency magnetron sputtering. The crystal structure, optical absorption, near-infrared luminescence, and ultraviolet photoresponse properties of Er:Ga2O3 films were systematically studied. The evolution of lattice and energy band gap with increasing doping level confirms the chemical substitution of Er3+ ions into the Ga2O3 crystal lattice. The down-shifting near-infrared luminescence (∼1538 nm: ascribed to Er3+: 4I13/2−4I15/2) was observed under ultraviolet excitation. Moreover, an obvious deep ultraviolet photoresponse was also obtained in the formed thin films.