ormation of a Low-resistance and High Reflectivity Reflector on p-type GaN with a AgAl Ohmic Contact

摘要

In this study, we investigate the effect of the Al composition of a AgA1 alloy reflector deposited on a p-GaN layer for use in a high-efficiency GaN flip-chip light-emitting diode (FCLED) or n-type side-up vertical LEDs. When the Al composition was 3%, the AgAl reflector showed low resistance, high reflectance and thermally stable ohmic contact properties. For an Al composition of 3% in the AgAl reflector, the optical output power was improved by 50%, and the current-voltage characteristic was improved compared to that for a Ag reflector. These results clearly indicate that a AgA1 layer on p-GaN constitutes a promising reflector and ohmic scheme for achieving high-brightness FCLEDs and vertical LEDs.