Effects of the V/III Ratio of a Low-Temperature GaN Buffer Layer on the Structural and Optical Properties of a-GaN Films Grown on r-Plane Sapphire Substrates by MOCVD
1Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074 2Department of Physics, Jianghan University, Wuhan 430056 3Department of Physics, Kangwon National University, Kangwon-do 200-701, Republic of Korea
Abstract：We investigate the effects of the V/III ratio of a low-temperature GaN buffer layer on the growth of the overlaying nonpolar -plane GaN film grown on -plane sapphire by metal-organic chemical-vapor deposition (MOCVD). With other experimental conditions keeping fixed, the low-temperature GaN buffer layers are grown under various V/III ratios of 1000, 3000, 6000 and 9000, respectively. The characteristics of the -plane GaN films are analyzed by scanning electron microscopy, high resolution x-ray diffraction, Raman spectrum, and low temperature photoluminescence. The results show that the V/III ratio of the buffer layer has significant effects on the crystal quality of the a-plane GaN film, and a V/III ratio of 6000 is found to be the most suitable condition to achieve pit-free flat GaN surface.
. [J]. 中国物理快报, 2012, 29(8): 88101-088101.
TIAN Yu, DAI Jiang-Nan, XIONG Hui, ZHENG Guang, RYU My, FANG Yan-Yan, and CHEN Chang-Qing. Effects of the V/III Ratio of a Low-Temperature GaN Buffer Layer on the Structural and Optical Properties of a-GaN Films Grown on r-Plane Sapphire Substrates by MOCVD. Chin. Phys. Lett., 2012, 29(8): 88101-088101.
2012, Vol. 29 
