Wang Zi-Wu, Sun Yong, Cui Yu, Xiao Yao, Deng Jia-Pei, Xiong Wen, Li Zhi-Qing
Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparing Technology, Department of Physics, School of Science, Tianjin University, Tianjin 300354, People's Republic of China.
Institute of Condensed Matter Physics, Inner Mongolia University for Nationalities, Tongliao 028043, People's Republic of China.
J Phys Condens Matter. 2021 Feb 16;33(14). doi: 10.1088/1361-648X/abdf92.
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 non-radiative 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 Fröhlich 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.
量子缺陷对于理解基于金属卤化物钙钛矿的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与光学声子之间耦合强度的黄-里斯因子在通过多声子过程确定非辐射复合中起着关键作用。在此，我们从理论上分别提出了在形变势和弗罗里希机制中由缺陷电荷载流子产生的缺陷介导的多声子拉曼散射，该缺陷与纵向光学（LO）声子耦合。我们发现拉曼散射在等间隔的LO声子处显示出多个LO声子泛音，其中黄-里斯因子可以通过最强泛音的阶数来评估。同时，我们给出了两种机制之间的组合多声子散射。具有弱散射强度的不同类型的组合模式为金属卤化物钙钛矿中长的非辐射电荷载流子寿命提供了一种可能的解释。
