Realization of p-GaN ohmic contact by using a strained p-AlInGaN interlayer and its application in UVA LEDs

Abstract

We use a p+-AlInGaN strained interlayer to form ohmic contact between p-GaN and indium tin oxide, and achieve a specific contact resistance of 6.06 × 10−2 Ω · cm2, similar to that with a p+-InGaN interlayer. When applied in a 365 nm UV LED, it shows a 0.5 V reduction of working voltage and an 18.1% enhancement of light output power, compared with those of the reference LED. Furthermore, the light output power is 12.8% higher than that of a LED with a p+-InGaN interlayer. These results indicate that a strained p-AlInGaN interlayer is a favorable choice for UVA LEDs.