Antisolvent-Treated MAPbI3 and PbS Quantum Dots for High- Performance Broadband Photodetectors

Nowadays, halide perovskites have drawn extensive attention as active layers in the field of photodetectors (PDs) attributed to their optoelectric properties. However, the numerous defects in the prepared films and the lack of response in the near-infrared (NIR) range due to the intrinsic band gap limitation severely restrict the performances and applications of perovskite photodetectors. With this in mind, we introduced diethyl ether as a counter-solvent to improve the quality of the peroxide films. After comparison with chlorobenzene (CB), toluene (ToL), and ethyl acetate (EA), the mechanism by which diethyl ether (DE) as an antisolvent improves the quality of the films was explored. MAPbI3 films and lead sulfide (PbS) quantum dots (QDs) were then combined to achieve a visible (VIS)-near-infrared response. The resultant PD, with the structure of ITO/NiOx/ PbS QDs/MAPbI3/PC61BM/Ag, exhibits an ultrabroad response from 300 to 1100 nm and presents high detectivity reaching 5.6 x 1011 and 6.5 x 1010 Jones in the VIS and NIR regions, respectively. The fast response time in the microsecond range and the response bandwidth of 10 kHz (f-3 dB) are comparable or even superior to counterparts. In addition, this approach provides ideas for the development of high-performance broadband perovskite-based optoelectronic devices.