Improved optical and electrical performances of GaN-based light emitting diodes with nano truncated cone SiO2 passivation layer

Abstract

GaN-based light emitting diodes (LEDs) with nano truncated cone SiO2 passivation layer via laser interference lithography and inductively coupled plasma dry etching technology were fabricated. The sidewall profile of the nano truncated cones was optimized by adjusting the etching process to obtain high fill factor. The light output power and electroluminescence intensity of the LEDs with textured SiO2 surface show better results than the conventional LEDs without SiO2 layer. At an injection current of 20 mA, the enhancement of the light output power is about 64 %. Moreover, the reverse leakage current, under a reverse bias of −5 V, is obviously reduced in contrast to the conventional LEDs. The method of texturing the passivation layers is proved to be an alternative method to improve both the optical and electrical performances of GaN-based LEDs.