Enhancement in light extraction of LEDs with SiO2 current blocking layer deposited on naturally textured p-GaN surface

Abstract

GaN-based light-emitting diodes (LEDs) with a SiO2 current blocking layer (CBL) deposited on naturally textured V-shaped pits (V-pits), grown on the p-GaN surface, was fabricated and investigated. The V-pits grown on p-GaN surface were used to increase photon scattering probability, and the SiO2 CBL was used to improve current spreading performance of the textured LED. Compared to the planar LED, the LED with naturally textured p-GaN surface exhibited 9.3% enhancement in light output power under 20mA injection current. At 20mA injection current, the LED with SiO2 CBL deposited on naturally textured p-GaN surface exhibited a 11.8% higher light output power than naturally textured LED without SiO2 CBL. Therefore, for a LED with V-pits grown on p-GaN surface, the light extraction efficiency can be further improved by employing a SiO2 CBL. The 20mA-driven forward voltage of textured LED with SiO2 CBL was only 0.04V higher than that of the textured LED.