Performance characteristics of GaN-based light-emitting diodes fabricated with AgNi, AgCu, and AgAl-alloy reflectors

Abstract

We report on the performance characteristics of GaN-based light-emitting diodes (LEDs) fabricated with Ag-alloy p-type reflectors including AgNi, AgCu, and AgAl. Compared to the reference LEDs fabricated with Ag, LEDs fabricated with AgNi and AgCu produced smaller forward voltages and higher light output power. Under optimized thermal annealing conditions, the forward voltages obtained were 3.56, 3.29, 3.28, and 3.44 V, the light output powers were 14.38, 15.73, 14.40, and 12.77 mW, and the power efficiencies were 20.2%, 23.91%, 21.95%, and 18.45% for LEDs fabricated with Ag, AgNi, AgCu, and AgAl, respectively. The surface morphology of Ag-alloy was also found to be smoother than that of Ag, suggesting that Ag-alloy reflectors, particularly AgNi, are very promising for practical applications.