The influence of organic molecular rotation on carrier Dynamics: A case of MAPbI3

Abstract

At room temperature, organic molecules undergo continuous rotation, driven by rotational barriers lower than k_BT. However, consensus regarding the impact of organic molecule rotation on carrier dynamics remains elusive, as conventional research methods struggle to distinguish between organic molecule rotation and inorganic frame vibrations. This study successfully achieved the goal of modulating the rotation rate of organic molecules by adjusting the relative atomic mass of nitrogen atoms. In the investigation of carrier dynamics, the rotational rate of organic molecules served as the sole independent variable. The findings indicate that a slower rotation rate correlates with an extended carrier lifetime. This correlation is attributed to the heightened charge separation and reduced motion of nuclei. This research provides valuable insights for prolonging the carrier lifetime of organic–inorganic hybrid perovskites.