Influence of polarities on optical properties of Mg-doped GaN films grown on GaN free-standing substrates by MOCVD
Influence of polarities on optical properties of Mg-doped GaN films grown on GaN free-standing substrates by MOCVD
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DOI：
10.1016/j.jlumin.2023.119740
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发表时间：
2023-05
影响因子：
3.6
通讯作者：
Sida Wei;Xiaodong Gao;Xiaodan Wang;Yangye Pan;Xionghui Zeng;Jiafan Chen;Shunan Zheng;Ke Xu
中科院分区：
文献类型：
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作者：
Sida Wei;Xiaodong Gao;Xiaodan Wang;Yangye Pan;Xionghui Zeng;Jiafan Chen;Shunan Zheng;Ke Xu
通过时间分辨光致发光测量，研究了通过 MOCVD 在 c 面、m 面和 (10-11) 面 GaN 独立衬底上生长的 p-GaN 薄膜的少数载流子复合机制。三个样品的快衰寿命和慢衰寿命通过双指数函数拟合，其中m面掺镁GaN的慢衰寿命达到了创纪录的长值493.7 ps？使用拉曼和 XRD 排除了应力引起的非辐射复合中心和边缘位错对慢衰变寿命的影响。 m 面样品的慢衰变寿命较长的原因是由于 VGa 浓度的降低而导致非辐射复合中心的减少，这由 PL 光谱中 IYL/INBE 比率的大小来保证。研究了 m 面样品的低温 PL 光谱。根据海恩斯规则，结合 5 K 处束缚激子的位置来校准受主能级的位置。
Time-resolved photoluminescence measurements were performed to investigate the minority carrier recombination mechanism of p-GaN films grown on c-plane, m-plane and (10–11)-plane GaN freestanding substrates by MOCVD. The fast and slow decay lifetimes of the three samples were fitted by the bi-exponential function, in which the slow decay lifetime of the m-plane Mg-doped GaN reached a record long value of 493.7 ps? The effects of stress-induced non-radiative recombination centers and edge dislocations on the slow decay lifetime were ruled out using Raman and XRD. The reason for the longer slow decay lifetime of the m-plane sample is the reduction of the non-radiative recombination centers due to the decrease of the VGaconcentration, ensuring by the magnitude of the IYL/INBEratio in the PL spectra. The low-temperature PL spectra of the m-plane sample were investigated. According to Haynes' rule, the position of acceptor level was calibrated through combining with the position of the bound excitons at 5 K.