Femtosecond Laser-Processed Perovskite Thin Films with Reduced Nonradiative Recombination and Improved Photodetecting Performance

Carrier recombination plays a key role in determining the performance of perovskite devices, wherein nonradiative recombination hinders carrier extraction and limits the performance of perovskite-based optoelectronic devices (e.g., solar cells and photodetectors). To reduce nonradiative recombination, passivating the surface and grain boundary defects with chemicals has been extensively studied. However, this method has limitations such as pollution, complicated procedures, etc. Here, we provide a physical approach to reduce the nonradiative recombination loss of MAPbI3 perovskite thin films using femtosecond (fs) laser processing. Perovskite thin films processed by fs laser show an enhanced photoluminescence (PL) intensity, extended lifetime, smaller grain size, smooth surface, and improved photodetector performance. The effect of laser processing is attributed to a decrease in the number of trap centers per grain and polished perovskite surface, which act as nonradiative recombination centers in the perovskite thin films. This research provides a promising way to improve the performance of perovskite optoelectronic devices.