Solution-Processed, Self-Powered Broadband CH₃NH₃PbI₃ Photodetectors Driven by Asymmetric Electrodes

In general, the fabrication of high-performance, self-powered broadband photodetectors based on traditional semiconducting thin films is tedious and costly. Here, in this paper a high-performance, solution-processed, and self-powered CH₃NH₃PbI₃ (MAPbI₃) nanocrystal based photodetector ITO/MAPbI₃/Ag is presented, and it shows broadband photoresponse from the visible to the near-infrared wavelength region. The pronounced enhanced performance of the photodetector is due to taking the advantage of the built-in electric field induced by the work function difference of two electrodes. The optimized photodetector shows a responsivity of 4.9 and 1.42 A W⁻¹ with a specific detectivity of 7.6 × 10¹³ and 1.77 × 10¹³ Jones under 19 µW cm⁻² white light illumination and 26 µW cm⁻² 808 nm illumination at zero bias, respectively. Therefore, such a concept of simple device geometry and feasible technique will open up a new and promising avenue for the fabrication of self-powered photodetectors and the development of imaging devices.