Effect of Cs Doping on the Carrier Dynamics of MAPbI Perovskite.

Organic inorganic perovskite materials have received increasing attention in the optoelectronic field because of their unique properties. The ultrafast dynamics of photogenerated carriers determine photoelectric conversion efficiency, thus, it is feasible to influence the dynamics behavior of photogenerated carriers by regulating A-site cations. This paper mainly used transient absorption spectra (TAS) technology to study the photogenerated carriers relaxation processes of organic-inorganic perovskite CsMAPbI materials at different x values. Three sets of time constants were obtained by global fitting at different values of x. The experimental results showed that the crystal structure of perovskite could be affected by adjusting the Cs doping amount, thereby regulating the carrier dynamics. The appropriate amount of A-cation doping not only maintained the organic-inorganic perovskite crystal phase, but also prolonged the photogenerated carrier's lifetime. The 10% Cs doping CsMAPbI perovskite has potential for solar cell applications. We hope that our research can provide dynamics support for the development of organic-inorganic perovskite in solar cells.