Investigation of CsSn_0.2Pb_0.8I₃ QDs applied to carbon-based self-powered perovskite photodetectors

The combination of the antisolvent method and additive passivation is an effective strategy to control the defects of organic-inorganic halide perovskite films. In this paper, CsSn_0.2Pb_0.8I₃ QDs prepared by the mixed heating method were mixed with toluene solution to form an anti-solvent of different concentrations, and defect passivation and modification of self-supplied carbon-based MAPbI₃ perovskite films were carried out. The results show that when the optimal additive concentration of 10 mg/mL CsSn_0.2Pb_0.8I₃ QDs optimized perovskite active layer is applied to the self-powered perovskite photodetector, the original dark current of the device is reduced from 1.09 × 10^− 9 A to 5.03 × 10^− 11 A, which is about 95%. Responsiveness reaches a maximum of 0.45 A/W, which is 28% higher than 0.35 A/W before optimization. Compared with the detection rate increased from 2.72 × 10¹² Jones to 2.53 × 10¹³ Jones (1 Jones = 1 cm∙Hz^1/2∙W^− 1), the detection capability of self-powered perovskite photodetector has been improved by nearly one order of magnitude.