GaN-Based LEDs Output Power Improved by Textured GaN/Sapphire Interface Using In Situ SiH₄ Treatment Process During Epitaxial Growth

In this study, we demonstrate aninsituroughening technique at the GaN/sapphire interface in GaN-based LEDs using a silane treatment (SiH4treatment) process that forms a thin SiNxlayer with nanometer-sized holes on the sapphire surface that behave like a patterned sapphire substrate. A plurality of voids at the GaN/sapphire interface is observed according to the transmission electron microscopy analysis. With a 20 mA current injection, the results indicate that the typical output power of LEDs grown with and without the SiH4treatment process are approximately 18.0 and 15.6 mW, respectively. In other words, the output power can be enhanced by 15% with the use of the SiH4treatment process. The enhancement of output power is mainly due to light scattering at the naturally textured GaN/sapphire interface, which can lead to a higher escape probability for the photons emitted from the active layer in an LED.