High-Efficiency InGaN/GaN Nanorod Arrays by Temperature Dependent Photoluminescence
WANG Wen-Jie1, CHEN Peng1,2**, YU Zhi-Guo1, LIU Bin1, XIE Zi-Li1, XIU Xiang-Qian1, WU Zhen-Long2, XU Feng2, XU Zhou2, HUA Xue-Mei1, ZHAO Hong1, HAN Ping1, SHI Yi1, ZHANG Rong1, ZHENG You-Dou1
1Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials and School of Electronic Science and Engineering, Nanjing University, Nanjing 210093 2Nanjing University Institute of Optoelectronics at Yangzhou, Yangzhou 225009
Abstract:We report on the photoluminescent characteristics of InGaN/GaN multiple quantum well (MQW) nanorod arrays with high internal quantum efficiency. The InGaN/GaN MQWs are grown by metalorganic chemical vapor deposition on c-plane sapphire substrates, and then the MQW nanorod arrays are fabricated by using inductively coupled plasma etching with self-assembled Ni nanoparticle mask with low-damage etching technique. The typical diameter of the nanorods is from 200 nm to 300 nm and the length is around 800 nm, which almost is dislocation free. At room temperature, an enhancement of 3.1 times in total integrated photoluminescence intensity is achieved from the MQW nanorod arrays, in comparison to that of the as-grown MQW structure. Based on the temperature-dependent photoluminescence measurements, the internal quantum efficiency of the nanorod structure is 59.2%, i.e., 1.75 times of as-grown MQW structure (33.8%). Therefore, the nanorod structure with a significant reduction of defects can be a very promising candidate for highly efficient light emitting devices.