Light-induced micro-strain regulation and charge carrier dynamics of (FA0.83MA0.17)0.95Cs0.05Pb(I0.83Br0.17)3 hybrid perovskite films

Abstract

Light-induced strategies are crucial for deciding the physical and chemical properties of organometal halide perovskite materials and their photovoltaic devices. Herein, the triple cation ((FA0.83MA0.17)0.95Cs0.05Pb(I0.83Br0.17)3) hybrid perovskite films have been fabricated using a simple solution-processed method. These films were illuminated by blue light (417 nm) for different time durations and characterized for structural, surface morphological, optical, and charge carrier dynamics. Under illumination conditions, a reduction in lattice micro-strain has been observed. The enhanced optical absorbance and reduced non-radiative recombination have also been monitored in light-illuminated perovskite films. Further, time-resolved photoluminescence (TRPL) and ultra-fast transient absorption spectroscopy (TAS) measurements have been performed to study the charge carrier dynamics. TRPL results show that the average lifetime of charge carriers has increased from 3 ns to 19 ns upon continuous light illumination conditions. Further, the recombination time of the charge carriers decreased from 226 ps to 66 ps upon continuous light illumination for 30 min. This study suggests that light-induced experiments on perovskite films can be utilized for micro-strain regulation and modulation of their charge carrier dynamics for future perovskite solar cell applications.