Nonradiative Dynamics Induced by Vacancies in Wide-Gap III-Nitrides: Ab Initio Time-Domain Analysis.
Nonradiative Dynamics Induced by Vacancies in Wide-Gap III-Nitrides: Ab Initio Time-Domain Analysis.
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DOI：
10.1021/acs.jpclett.3c01515
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发表时间：
2023-07
期刊：
影响因子：
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通讯作者：
Yuxin Yang;Z. Shi;Shoufeng Zhang;Xiaobao Ma;Jiangxiao Bai;Dashuo Fan;H. Zang;Xiaojuan Sun
中科院分区：
文献类型：
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作者：
Yuxin Yang;Z. Shi;Shoufeng Zhang;Xiaobao Ma;Jiangxiao Bai;Dashuo Fan;H. Zang;Xiaojuan Sun
对缺陷特性的深刻理解和缺陷损伤的预防是基于宽间隙iii -氮化半导体的光电子器件发展的最大问题之一。本文通过从头算分子动力学和非绝热（NA）量子动力学模拟，研究了宽间隙iii型氮化物（GaN， AlN和AlxGa1-xN）中空位诱导的载流子非辐射动力学，因为外延样品中存在相当大的缺陷密度。E-h复合几乎不受Vcation的影响，在VBM附近形成了浅态。我们的研究结果表明，与Shockley-Read-Hall （SRH）模型一样，AlN中的VN创造了缺陷辅助的非辐射重组中心，并缩短了重组时间（τ）。在GaN中，VN改善了CBM和VBM之间的NA耦合。此外，增加AlxGa1-xN合金中x的含量可以加速非辐射复合，这可能是进一步提高高al含量AlxGa1-xN合金IQE的重要问题。这些发现对于改进宽间隙iii -氮化物基光电子器件具有重要意义。
Insightful understanding of defect properties and prevention of defect damage are among the biggest issues in the development of photoelectronic devices based on wide-gap III-nitride semiconductors. Here, we have investigated the vacancy-induced carrier nonradiative dynamics in wide-gap III-nitrides (GaN, AlN, and AlxGa1-xN) by ab initio molecular dynamics and nonadiabatic (NA) quantum dynamics simulations since the considerable defect density in epitaxy samples. E-h recombination is hardly affected by Vcation, which created shallow states near the VBM. Our findings demonstrate that VN in AlN creates defect-assisted nonradiative recombination centers and shortens the recombination time (τ) as in the Shockley-Read-Hall (SRH) model. In GaN, VN improves the NA coupling between the CBM and the VBM. Additionally, increasing x in the AlxGa1-xN alloys accelerates nonradiative recombination, which may be an important issue in further improving the IQE of high Al-content AlxGa1-xN alloys. These findings have significant implications for the improvement of wide-gap III-nitrides-based photoelectronic devices.