Nonradiative Dynamics Induced by Vacancies in Wide-Gap III-Nitrides: Ab Initio Time-Domain Analysis

• Published in: The journal of physical chemistry letters 2023-07, Vol.14 (29), p.6719-6725
• Main Authors: Yang, Yuxin, Shi, Zhiming, Zhang, Shoufeng, Ma, Xiaobao, Bai, Jiangxiao, Fan, Dashuo, Zang, Hang, Sun, Xiaojuan, Li, Dabing
• Format: Article
• Language: English
• Subjects: Physical Insights into Energy Science
• ISSN: 1948-7185; 1948-7185
• DOI: 10.1021/acs.jpclett.3c01515

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 Al x Ga1–x N) 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 Al x Ga1–x N alloys accelerates nonradiative recombination, which may be an important issue in further improving the IQE of high Al-content Al x Ga1–x N alloys. These findings have significant implications for the improvement of wide-gap III-nitrides-based photoelectronic devices.