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

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 20 mA injection current. At 20 mA 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 20 mA-driven forward voltage of textured LED with SiO2 CBL was only 0.04 V higher than that of the textured LED.

► LEDs with SiO2 CBL and textured p-GaN exhibit 11.8% higher optical power. ► A SiO2 CBL is used to achieve better current spreading performance. ► The V-pits grown on p-GaN are used to increase photon scattering probability.