Strain effects on the polarized optical properties of InGaN with different In compositions
Strain effects on the polarized optical properties of InGaN with different In compositions
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DOI：
10.1088/1674-1056/18/6/080
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发表时间：
2009
影响因子：
1.7
通讯作者：
Tao Ren-Chun;Yu Tong-Jun;Jia Chuan-Yu;Chen Zhi-zhong;Qin Zhi-Xin;Zhang Guo-yi
中科院分区：
文献类型：
--
作者：
Tao Ren-Chun;Yu Tong-Jun;Jia Chuan-Yu;Chen Zhi-zhong;Qin Zhi-Xin;Zhang Guo-yi
通过分析与前三个价带(Vbs)相关的三个跃迁的相对振子强度(ROS)和能级分裂，讨论了不同In组分(x=0，0.0 5，0.10，0.15)对c面和m面InxGa1−xN偏振光学性质的应变效应.用基于k·p微扰理论的有效质量哈密顿量计算了ROS。对于c平面InxGa1−xN，发现类|X)和类Y)态的ROS相互叠加。特别是在压缩应变作用下，它们主要分布在Vb的顶部，其能级也随着应变的增加而增加，而类Z(Z)态的ROS则在第二带降低。对于m平面压缩应变InxGa1−xN，前三个VB分别以类|X)、|Z)和|Y)态为主，导致近线偏振光发射。对于顶部Vb，类|X)和类Z)态之间的ROS差异随着压缩应变的增大而增大。研究还发现，这种趋势在成分含量较高的蛋鸡中更为明显。结果表明，无论是c面还是m面InGaN的总发射中都有更多的TE模存在，同时也会产生更多的压缩应变和内容，导致偏振度更大。对InGaN/GaN量子阱(QW)发光的实验结果与我们的计算结果符合得很好。
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.