Strain effects on the polarized optical properties of InGaN with different In compositions  

作　　者：陶仁春 于彤军 贾传宇 陈志忠 秦志新 张国义 

机构地区：[1]State Key Laboratory for Mesoscopic Physics,School of Physics,Peking University

出　　处：《Chinese Physics B》2009年第6期2603-2609,共7页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China (Grant Nos 60676032,60577030 and 60776042);National Key Basic Research Special Foundation of China (Grant No TG 2007CB307004)

摘　　要：Strain effects on the polarized optical properties of c-plane and m-plane InxGa1-xN were discussed for different In compositions （x = 0, 0.05, 0.10, 0.15） by analyzing the relative oscillator strength （ROS） and energy level splitting of the three transitions related to the top three valence bands （VBs）. The ROS was calculated by applying the effective-mass Hamiltonian based on k .p perturbation theory. For c-plane InxGa1-xN, it was found that the ROS of 〈X〉 and 〈Y〉-like states were superposed with each other. Especially, under compressive strain, they dominated in the top VB whose energy level also went up with strain, while the ROS of the ｜Z〉-like state decreased in the second band. For m-plane InxGa1-xN under compressive strain, the top three VBs were dominated by 〈X〉, 〈Z〉, and 〈Y〉-like states, respectively, which led to nearly linearly-polarized light emissions. For the top VB, ROS difference between [X） and [Z）-like states became larger with compressive strain. It was also found that such tendencies were more evident in layers with higher In compositions. As a result, there would be more TE modes in total emissions from both c-plane and m-plane InGaN with compressive strain and In content, leading to a larger polarization degree. Experimental results of luminescence from InGaN/GaN quantum wells （QWs） showed good coincidence with our calculations.Strain effects on the polarized optical properties of c-plane and m-plane InxGa1-xN were discussed for different In compositions （x = 0, 0.05, 0.10, 0.15） by analyzing the relative oscillator strength （ROS） and energy level splitting of the three transitions related to the top three valence bands （VBs）. The ROS was calculated by applying the effective-mass Hamiltonian based on k .p perturbation theory. For c-plane InxGa1-xN, it was found that the ROS of 〈X〉 and 〈Y〉-like states were superposed with each other. Especially, under compressive strain, they dominated in the top VB whose energy level also went up with strain, while the ROS of the ｜Z〉-like state decreased in the second band. For m-plane InxGa1-xN under compressive strain, the top three VBs were dominated by 〈X〉, 〈Z〉, and 〈Y〉-like states, respectively, which led to nearly linearly-polarized light emissions. For the top VB, ROS difference between [X） and [Z）-like states became larger with compressive strain. It was also found that such tendencies were more evident in layers with higher In compositions. As a result, there would be more TE modes in total emissions from both c-plane and m-plane InGaN with compressive strain and In content, leading to a larger polarization degree. Experimental results of luminescence from InGaN/GaN quantum wells （QWs） showed good coincidence with our calculations.

关 键 词：GaN polarization degree M-PLANE relative oscillator strength 

分 类 号：O472.3[理学—半导体物理]