Yellow emission from vertically integrated Ga2O3 doped with Er and Eu electroluminescent film

Highlights: • Vertically integrated yellow LED based on Ga₂O₃:(Er + Eu) film was fabricated. • Yellow light can be observed with the naked eyes at a low driven voltage of 10 V. • Parameter of yellow light in chromaticity diagram was calculated as (0.4379, 0.5343). • The electroluminescence and transport mechanism were understood. Yellow color from vertically integrated light emitting device (LED) was reported. The multilayer structured Er and Eu doped Ga₂O₃ films were deposited on sapphire and GaAs substrates by alternate-target pulsed laser deposition. The structure, surface morphology, and optical properties of the films were systematically investigated. Bright yellow electroluminescence originated from the combined simultaneous emission of excited Er³⁺ (529, 550 nm) and Eu³⁺ (615 nm) can be observed with the naked eyes at a low driven voltage of 10 V. Parameters of the yellow emission for the chromaticity diagram were calculated to be x = 0.4379, y = 0.5343. It is determined that the optically active Er and Eu ions are simultaneously activated by defect-assisted carrier recombination excitation. We believe that this work will provide a prospect for realizing low-voltage driven color LED using rare earth doped Ga₂O₃ films.