The ultrafast carrier dynamics in 2-D heterostructures is crucial for photocatalytic performance during clean energy production while designing it rationally is a challenge. Herein, we combine first-principles calculations with nonadiabatic molecular dynamics (NAMD) methods to unravel ultrafast carrier dynamics in two novel 2-D heterostructures, GaN/SnS₂ and GaN/HfS₂, to explore the rational design methods of ultrafast carrier dynamics. Despite the similar electronic ground-state properties of the two heterostructures, NAMD simulations reveal significant differences in their ultrafast carrier dynamics. The GaN/SnS₂ heterostructure exhibits faster interlayer carrier recombination and slower interlayer electron transfer rate compared to the GaN/HfS₂ heterostructure. The in-depth study reveals that carrier dynamics is related to nonadiabatic coupling elements (NACs). Charges distributed at the interface of the heterostructure and highly delocalized wavefunctions facilitate strong NACs, thereby accelerating interlayer carrier recombination. Conversely, weak NACs, resulting from large energy level differences, delay the transfer of photogenerated electrons. This work reveals the influencing factors of ultrafast carrier dynamics in 2-D heterostructures and provides theoretical guidance for the rational design of high-performance 2-D photocatalytic heterostructures for renewable energy applications.

中文翻译：

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揭示光催化二维异质结构中的超快载流子动力学：来自第一性原理和非绝热分子动力学的见解


二维异质结构中的超快载流子动力学对于清洁能源生产过程中的光催化性能至关重要，而合理设计它是一个挑战。在此，我们将第一性原理计算与非绝热分子动力学（NAMD）方法相结合，揭示了两种新型二维异质结构GaN/SnS ₂和GaN/HfS ₂中的超快载流子动力学，探索超快载流子动力学的合理设计方法。尽管两种异质结构具有相似的电子基态特性，但 NAMD 模拟揭示了它们的超快载流子动力学存在显着差异。与GaN/HfS ₂异质结构相比，GaN/SnS ₂异质结构表现出更快的层间载流子复合和更慢的层间电子转移速率。深入研究表明，载流子动力学与非绝热耦合元件（NAC）有关。分布在异质结构界面的电荷和高度离域的波函数有利于强NAC，从而加速层间载流子复合。相反，由于能级差异较大，NAC 较弱，会延迟光生电子的转移。这项工作揭示了二维异质结构中超快载流子动力学的影响因素，为合理设计用于可再生能源应用的高性能二维光催化异质结构提供了理论指导。