Enhanced Optical Output Power of Blue Light-Emitting Diode Grown on Sapphire Substrate with Patterned Distributed Bragg Reflector

摘要

We demonstrate InGaN-based blue light-emitting diodes (LEDs) with embedded SiO2/SiNx distributed Bragg reflectors (DBRs). Five pairs of circular SiO2/SiNx DBRs were fabricated on a sapphire substrate by depositing multiple dielectric layers and patterning. At an injection current of 20 mA, the optical output power of the LEDs with circular DBRs was 33% higher than that of conventional LEDs without DBRs. The enhancement of optical output power is attributed to the improved light extraction efficiency and internal quantum efficiency of an LED caused by inserting the highly reflective circular DBRs, which increase the reflection of light from the substrate and increase the internal quantum efficiency by reducing threading dislocations in the GaN epilayer. (c) 2018 The Electrochemical Society.