Self-powered nn heterojunction UV imaging photodetectors based on in-situ-grown MAPbCl3 microplates on GaN substrates

Self-powered ultraviolet (UV) photodetectors are widely applicable in various fields due to their ability to operate autonomously, offering unparalleled portability and flexibility. In this letter, a high-performance self-powered UV photodetector based on GaN/MAPbCl 3 microplate nn heterojunction is demonstrated. The n-MAPbCl 3 microplates were grown in situ on the n-GaN substrate using a simple solution process. Thanks to the differences in the energy band between MAPbCl 3 and GaN, a built-in electric field is formed, which facilitates efficient separation of photogenerated charge carriers. This enables the photodetector to operate without the need of an external bias voltage. Furthermore, the wide bandgap of both MAPbCl 3 and GaN endows the photodetector with exceptional sensitivity to UV light. The optimized GaN/MAPbCl 3 device exhibits high-performance metrics, including low dark current and noise, high photo to dark current ratio, responsivity, and detectivity at zero bias.