金属卤化物钙钛矿半导体中的自陷激子

Self-trapped Excitons in Metal Halide Perovskites

在极性晶体中,由于强电子–声子耦合,激发的电子–空穴对可以被晶格畸变产生的形变势场所俘获,形成自陷激子。金属卤化物钙钛矿半导体作为一种离子晶体已经被证实具有高效的自陷激子发光,成为制备新一代高质量白光光源的理想候选材料。然而,对于金属卤化物钙钛矿中自陷激子发光机制的理解仍然较为匮乏,远远落后于器件方面的发展。为此,本文主要从自陷激子的基础物理角度出发,总结了近年来关于金属卤化物钙钛矿半导体中自陷激子的形成条件、形成机制以及相关激发态动力学的研究进展,并对未来基于该体系中自陷激子机理方面的研究做出展望,从而为该体系中自陷激子的研究提供更加清晰的物理图像。

In polar crystals,excited electron-hole pairs can be captured by the deformation potential field created by lattice distortion upon photoexcitation,due to strong electron-phonon interactions,thereby forming self-trapped excitons.Metal halide perovskites are semiconductors that display efficient self-trapped exciton luminescence in various systems due to their ionic crystal nature with strong electron-phonon interactions and a deformable lattice.Consequently,they are considered ideal for creating high-quality white light sources.However,the understanding of the self-trapped exciton luminescence mechanism in metal halide perovskites is still relatively scarce and lags far behind the development of devices.To this end,this paper summarizes the recent research progress on the formation conditions,formation mechanism and related excited state dynamics of self-trapped excitons in metal halide perovskites semiconductors from the perspective of the fundamental physics of self-trapped excitons,and gives an outlook on the future research based on the self-trapped exciton mechanism in this system,so as to provide a clearer physical image for the study of self-trapped excitons in this system.