High-Performance GaN-Based Light-Emitting Diodes on Patterned Sapphire Substrate with a Novel Patterned SiO2/Al2O3Passivation Layer

GaN-based light-emitting diodes (LEDs) on patterned sapphire substrate (PSS) with a novel patterned SiO 2 /Al 2 O 3 passivation layer have been proposed and fabricated. Due to the excellent uniformity and compactness of atomic layer deposition (ALD) for the first Al 2 O 3 layer, a high passivation effect has been achieved. The second SiO 2 layer with patterned hemisphere arrays decreases the total internal reflection (TIR) and, hence, increases the light output power (LOP). With a 60 mA injection current, an enhancement of 21.6% in LOP was realized for the LED with an appropriately patterned SiO 2 /Al 2 O 3 passivation layer as compared with the conventional LED with a SiO 2 passivation layer.