高效率多孔隙氮化銦鎵發光元件研製

High-Efficiency InGaN-based Light-Emitting Diodes with Nanoporous GaN:Mg Structure

10.6409/JMSE.200612.0223

黃立陽(L.Y. Huang)；張政謙(C.C. Chang)；謝秉承(P.C. Hsieh)；楊仲傑(C.C. Yang)；林佳鋒(C.F. Lin)

氮化鎵 ； 光致電化學氧化 ； 多孔隙結構 ； 壓電場效應 ； nanoporous GaN:Mg ； InGaN-based Light-Emitting Diodes ； photoelectrochemical PEC

材料科學與工程

38卷4期（2006 / 12 / 01）

223 - 227

繁體中文

本實驗將針對多孔隙氮化鎵拉米結構進行研究，採用光致電化學氧化技術將氮化鎵磊晶層氧化蝕刻形成多孔隙結構，應用於氮化銦鎵發光元件之P型氮化鎵表面粗化，製作高效率發光元件，研究元件特性如下：(1)多孔隙P型氮化鎵表面對光散射與破壞全反射有助於提升光取出效率。(2)多孔隙P型氮化鎵結構釋放氮化銦鎵發光層所受之壓縮應力，使壓電場效應減少並提升電子電洞結合效率對發光效率。(3)在電激發光光性量測上，多孔隙氮化鎵發光元件中觀察到發光波長藍移與發光效率提升之效應。

In this research nanoporous structures on p-type GaN:Mg and n-type GaN:Si surfaces were fabricated through a photoelectrochemical (PEC) oxidation and an oxide-removing process. The photoluminescence (PL) intensities of GaN and InGaN/GaN multi-quantum-well (MQW) structures were enhanced by forming this nanoporous structure to increase light extraction efficiency. The PL emission peaks of an MQW active layer have a blueshift phenomenon from 465.5 nm (standard) to 456.0 nm (nanoporous) measured at 300 K which was caused by partially releasing the compressive strain from the top GaN:Mg layers. The internal quantum efficiency could be increased by a partial strain release that induces a lower piezoelectric field in the active layer. The thermal activation energy of a nanoporous structure (85 meV) is higher than the standard one (33 meV) from a temperature dependent PL measurement. The internal quantum efficiency and light extraction efficiency of an InGaN/GaN MQW active layer are significantly enhanced by this nanoporous GaN:Mg surface, and this PEC treated nanoporous structure is suitable for high-power lighting applications.