Experiments have demonstrated that defect states can regulate the charge carrier dynamics in heterojunctions. However, the underlying mechanism still remains under debate. Using nonadiabatic molecular dynamics, we have investigated the influence of inter and intraband defect states on charge relaxation in InSe/SiH heterojunctions. The simulations revealed that inter and intraband defect states have a weak effect on electron transfer, whereas they exert a strong influence on hole transfer and electron–hole recombination. Compared to the pristine system, the selenium vacancy creates two interband shallow electron trapping states and one intraband hole trapping state. The interband electron trapping states can capture photo-generated electrons, while the intraband hole trapping state accelerates hole transfer. The synergy between inter and intraband defect states suppresses the charge recombination by a factor of 8.3. This simulation rationalizes the influence mechanism of inter and intraband defect states on charge carrier dynamics, suggesting a valuable principle for enhancing the performance of heterojunction photocatalysts.

中文翻译：

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带间和带内缺陷状态之间的协同作用，延长 InSe/SiH 异质结的电荷载流子寿命


实验表明，缺陷态可以调节异质结中的电荷载流子动力学。然而，其潜在机制仍存在争议。利用非绝热分子动力学，我们研究了带内和带内缺陷状态对 InSe/SiH 异质结中电荷弛豫的影响。仿真结果表明，带间和带内缺陷态对电子转移的影响较弱，而它们对空穴转移和电子-空穴复合的影响很大。与原始系统相比，硒空位产生两个带间浅电子俘获态和一个带内空穴俘获态。带间电子俘获态可以捕获光生电子，而带内空穴俘获态会加速空穴转移。带内缺陷状态和带内缺陷状态之间的协同作用将电荷复合抑制了 8.3 倍。该仿真合理化了带内和带内缺陷态对电荷载流子动力学的影响机制，为提高异质结光催化剂的性能提出了有价值的原理。