Passivating the vacancy defects of CsPbCl3 polycrystalline films by a Cl-containing ionic liquid for self-powered, charge-transport-layer-free UV photodetectors

A defect passivation strategy using [BMMIm]Cl ion liquid is demonstrated for the fabrication of high-performance, charge-transport-layer-free CsPbCl 3 UV photodetectors, achieveing an ultrahigh on/off ratio of 2.70 × 10 5 at 0 V bias.