Quantum defects are essential to understand the non-radiative recombination processes in metal halide perovskites-based photovoltaic devices, in which Huang-Rhys factor, reflecting the coupling strength between the charge carrier and optical phonons, plays a key role in determining the nonradiative recombination via multiphonon processes. Herein, we theoretically present multiphonon Raman scattering intermediated by defects arising from the charge carrier of defect coupled with the longitudinal optical (LO) phonon in the deformation potential and Fr¨ohlich mechanisms, respectively. We find that the Raman scattering shows multiple LO phonon overtones at equal interval LO phonons, where Huang-Rhys factor could be evaluated by the order of the strongest overtone. Meanwhile, we give the combinational multiphonon scattering between two mechanisms. Different types of the combinational modes with the weak scattering intensities provide a possible explanation for the long non-radiative charges-carrier lifetimes in metal halide perovskites.

中文翻译：

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金属卤化物钙钛矿中的量子缺陷辅助多声子拉曼散射

量子缺陷对于理解金属卤化物钙钛矿基光伏器件中的非辐射复合过程至关重要，其中反映电荷载流子和光学声子之间耦合强度的 Huang-Rhys 因子在确定非辐射复合过程中起关键作用。多声子过程。在这里，我们理论上提出了由缺陷的电荷载流子引起的缺陷与变形势和Fr¨ohlich机制中的纵向光学（LO）声子耦合产生的多声子拉曼散射。我们发现拉曼散射在等间隔 LO 声子处显示多个 LO 声子泛音，其中 Huang-Rhys 因子可以通过最强泛音的顺序来评估。同时，我们给出了两种机制之间的组合多声子散射。