High-efficiency GaN-based light-emitting diodes fabricated with identical Ag contact formed on both n- and p-layers

The authors report high-efficiency GaN-based light-emitting diodes (LEDs) fabricated with identical Ag contact formed on both n- and p-layers. Ag contacts thermally annealed at optimized conditions yielded low specific contact resistances of 4.5 × 10(-4) and 9.4 × 10(-4) Ωcm(2), and high optical reflectivity (at 450 nm) of 88.1 and 85.3% for n- and p-contact, respectively. LEDs fabricated with identical Ag contacts formed on both layers showed 31% brighter light output power and nearly the same forward voltages as compared to reference LEDs. This indicates that Ag contact can be used as a reflective electrode for both n- and p-layers, leading to enhanced extraction efficiency and fewer process steps.