Enhancement in Light Extraction Efficiency of GaN-Based Light-Emitting Diodes Using Double Dielectric Surface Passivation

• 作者: Chung-Mo Yang Dong-Seok Kim Jae-Hoon Lee Jung-Hee Lee Yong Soo Lee Yun Soo Park
• 来源期刊: 光学与光子学期刊(英文)
• 学科: 工学
• 关键词: GaN LIGHT-EMITTING DIODE (LED) Al2O3 PEALD PASSIVATION DOUBLE DIELECTRIC STACK Layer
• 年，卷（期）: 2012,（3）
• 页码范围: 185-192
• 页数: 8页
• 分类号: TN3

摘要

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.