Enhanced photoresponsiveness of methylammonium lead iodide nanoplates via high pressure quenching

Organic-inorganic halide perovskites (HOIPs) are promising light-electric conversion materials for optoelectronic devices. Improving the light responsiveness properties of HOIPs is of great significance for the development of the optoelectronics industry. In this study, we have investigated the effect of pressure on the optoelectronics properties of the archetypical representative HOIPs methylammonium lead iodide nanoplates. An enhancement of the photocurrent accompanied by 4 times-prolonged carrier lifetime, enhanced photoluminescence (PL) intensity, and narrowed bandgap were observed via applying pressure to about 0.36 GPa, while these physical properties got worse with further compression. Strikingly, when released to ambient conditions, the photocurrent is further increased to 4.5 times and the carrier lifetime is prolonged to 1.5 times of the corresponding values for an initial sample, while the bandgap slightly blueshifted and the PL intensity slightly reduced. These results suggest that the increased photocurrent may be related to the increased carrier lifetime of the quenched sample, which gives more time for the separation of photoelectrons from vacancies before recombination. This study demonstrated that pressure engineering can be a real possibility for improving the light responsiveness of the HOIPs material in practical applications.