AI 中文总结
研究金属卤化物钙钛矿中电荷载流子的超精细驱动自旋弛豫，采用为μ子自旋光谱开发的模型，揭示不同弛豫通道，预测含特定元素钙钛矿自旋寿命延长，提取微观参数，为相关研究提供见解和框架。
AI 中文摘要
半导体中局域电荷载流子的自旋弛豫主要由与周围核自旋库的超精细相互作用决定。虽然这种机制在III-V族体材料和量子点中已得到充分证实，但其在金属卤化物钙钛矿（MHP）中的关键作用最近才显现出来。其倒置的能带结构导致了超精细耦合的异常层次结构，空穴相互作用主导电子相互作用，特别是在铅基钙钛矿中。在这里，我们采用了一种最初为μ子自旋光谱开发的自旋弛豫模型，以精确描述任意超精细相关时间内局域载流子的纵向自旋弛豫。这种方法是受MAPbI3中最近的实验证据启发，该证据将载流子自旋置于传统单指数近似失效的中间相关区域。我们的分析揭示了不同的超精细弛豫通道：电子主要与卤素核耦合，而空穴则由金属核控制。这导致了一个关键预测——含有较轻卤素和金属阳离子的钙钛矿表现出显著延长的自旋寿命。将我们的模型应用于从两个钙钛矿样品获得的时间分辨法拉第旋转数据，提取了关键的微观参数，包括载流子局域体积和超精细相关时间，证明了精确动力学解相对于单指数近似的必要性。这些发现为MHP中超精细驱动的自旋弛豫提供了微观见解，并建立了一个强大的框架来表征载流子局域化和自旋动力学。
英文摘要
Spin relaxation of localized charge carriers in semiconductors is primarily governed by hyperfine interaction with the surrounding nuclear spin bath. While this mechanism is well-established in III-V bulk materials and quantum dots, its critical role in metal halide perovskites (MHPs) has only recently emerged. Their inverted band structure induces an unusual hierarchy of hyperfine couplings, with hole interactions dominating electron interactions, particurlaly in Pb-based perovskites. Here, we adapt a spin relaxation model - originally developed for muon spin spectroscopy - to provide an exact description of longitudinal spin relaxation for localized carriers across arbitrary hyperfine correlation times. This approach is motivated by recent experimental evidence in MAPbI3, which places carrier spins in an intermediate correlation regime, where conventional mono-exponential approximations fail. Our analysis reveals distinct hyperfine relaxation channels: electrons couple primarily to halogen nuclei, whereas holes are governed by metal nuclei. This leads to a key prediction - perovskites with lighter halogens and metal cations exhibit significantly extended spin lifetimes. Applied to time-resolved Faraday rotation data obtained from two perovskite samples, our model extracts key microscopic parameters - including the carrier localization volume and hyperfine correlation time - demonstrating the necessity of the exact dynamical solution over a single-exponential approximation. These findings provide microscopic insight into hyperfine-driven spin relaxation in MHPs and establish a robust framework for characterizing carrier localization and spin dynamics.
