Charge Carrier Dynamics of Organic Cation-Treated Perovskites Probed with Time-Resolved Microwave Conductivity

Abstract

Metal halide perovskites have emerged as a set of promising optoelectronic materials benefiting from their outstanding optoelectronic properties and unprecedented success in photovoltaics. Recent studies have suggested that mixing lower-dimensional A-site cations within perovskites helps mitigate this environmental and phase instability for 3D perovskites. However, the charge carrier transport properties in mixed 2D/3D perovskites are still not fully understood. In this work, charge carrier mobilities and recombination rate constants in perovskite thin films were analyzed with transient time-resolved microwave conductivity and time-resolved photoluminescence. It was found that upon large-cation treatment of 3D perovskites, charge carrier transport and radiative recombination efficiency were enhanced by the passivation of surface defects, which is evidenced by the decay dynamics of charge carriers.