Broadband Ultraviolet Photodetectors Based on Cerium Doped Lead-Free Cs<sub>3</sub>MnBr<sub>5</sub> Metal Halide Nanocrystals
Long Shao, Donglei Zhou, Nan Ding, Rui Sun, Wen Xu, Nan Wang, Shihan Xu, Dali Liu, Hongwei Song
Abstract
Lead halide perovskites are widely used for optoelectronic devices because they possess a high charge carrier mobility, high photoconversion efficiency, low energy cost, etc. However, lead toxicity and instability of these perovskites prevent their wide-scale industrial applications. Herein, we successfully fabricated the lead-free Ce3+ doped Cs3MnBr5 metal halide nanocrystals (MHNCs), which displays a broad UV response and an efficient blue photoluminescence at 398 and 423 nm. The introduction of Ce3+ ions results in a broadband response to UV light, a highly improved photoluminescence quantum yield from 38% to 90%, and an improved longtime stability. The highly desirable broadband UV photodetector was fabricated based on the Ce3+ doped Cs3MnBr5 MHNCs film, which shows a broadband response to UV light ranging from 200 to 380 nm. The responsivity was 1.1 A/W with a millisecond rise/fall time response. This study demonstrates a strategy of fabricating the broadband UV photodetector for novel and advanced UV optoelectronic systems.