Author(s)

Chung-Mo Yang, Dong-Seok Kim, Yun Soo Park, Jae-Hoon Lee, Yong Soo Lee, Jung-Hee Lee

GaN Power Research Group, R&D Institute, Samsung LED Co., Ltd, Suwon, Republic of Korea.
School of Electrical Engineering and Computer Science Kyungpook National University, Daegu, Republic of Korea.

SiO₂Al₂O₃ double dielectric stack layer was deposited on the surface of the GaN-based light-emitting diode (LED). The double dielectric stack layer enhances both the electrical characteristics and the optical output power of the LED because the first Al₂O₃ layer plays a role of effectively passivating the p-GaN surface and the second lower index SiO₂ layer increases the critical angle of the light emitted from the LED surface. In addition, the effect of the Fresnel reflection is also responsible for the enhancement in output power of the double dielectric passivated LED. The leakage current of the LED passivated with Al₂O₃ layer was -3.46 × 10^-11 A at -5 V, at least two and three orders lower in magnitude compared to that passivated with SiO₂ layer (-7.14 × 10^-9 A) and that of non-passivated LED (-1.9 × 10^-8 A), respectively, which indicates that the Al₂O₃ layer is very effective in passivating the exposed GaN surface after dry etch and hence reduces nonradiative recombination as well as reabsorption of the emitted light near the etched surface.

GaN; Light-Emitting Diode (LED); Al₂O₃; PEALD; Passivation; Double Dielectric Stack Layer

Yang, C. , Kim, D. , Park, Y. , Lee, J. , Lee, Y. and Lee, J. (2012) Enhancement in Light Extraction Efficiency of GaN-Based Light-Emitting Diodes Using Double Dielectric Surface Passivation. Optics and Photonics Journal, 2, 185-192. doi: 10.4236/opj.2012.23028.