Hot Carrier Localization Affected by A Cations in Hybrid Perovskite

Abstract

Although FAPbI₃-based optoelectronic devices have achieved excellent properties, the role of organic cations FA and MA in the performance of organic-inorganic perovskites remains contentious. These cations typically affect the phase stabilization, cubic crystallization, and surface functionalization process, while were traditionally believed to hardly directly affect the optoelectronic properties of organic-inorganic lead halide perovskites (OLHPs). In this study, transient photo-drag current, arising from momentum transfer during light-matter interaction, is employed to reveal the hot carrier transfer dynamics of the OLHPs. The photo-drag current could be reversed by the substitution of the MA cation, which indicates the hot carriers in OLHPs are strongly localized by the MA cation dipole. Additionally, the correlation between the hot carrier photoconductivity and the electronic structure in different A-cation samples revealed that the bulk photovoltaic current could also affected by the A-cation in HIOPs. Our work not only demonstrates the photon drag current in perovskite with an excess photon energy pump but also provides a method to study light-carrier-phonon interactions of the hot carriers in OLHPs.