Low driven voltage red LEDs using Eu-doped Ga2O3 films on GaAs

Red LEDs based on Eu:Ga2O3/GaAs heterojunctions were fabricated using a pulsed laser deposition method. Eu-related luminescence originating from the D-5(0)-F-7(2) transition of Eu3+ was observed at about 611 nm. Bright red light can be observed with the naked eye at 6.0 V. Under forward bias, the electrons will first transit to the defect-related energy levels and then recombine with holes. The indirect recombination of carriers in the Ga2O3 host could transfer energy to the Eu ions. This work will provide an outlook for future low driven voltage and small-scale displays. (C) 2019 The Japan Society of Applied Physics