Suppressing leakage current by interfacial engineering for highly sensitive, broadband, self-powered FACsPbI₃ perovskite photodetectors

Dark current is considered as one of the important parameters to suppress temporal noise and enhance sensitivity of photodetectors. This study shows the effect of active layer thickness and different interfacial layers in the suppression of leakage current. High-sensitivity (D* > 10(12) Jones) perovskite photodetectors (PPDs) are fabricated using the device structure of ITO/PEDOT: PSS/FA(0.95)Cs(0.05)PbI(3) (d(PVSK))/ electron transport layer (ETL)/BCP/Ag with noise current <1 pA Hz(-1/2). These PPDs have a broadband response from near-ultraviolet to near-infrared region (300-840 nm). The overall performance of the PPDs enhanced for the optimal thickness of active layer of d(PVSK) = 600 nm and ETL PC60BM layer thickness of d(ETL) = 50 nm. The total noise current of the PPD is further suppressed by replacing the ETL PC60BM (i(n) = 63.11 fA Hz(-1/2)) layer by a PC70BM (i(n) = 33.41 fA Hz(-1/2)) layer. This further improved other figures of merit for these PPDs. Comparison with published reports on PPDs is included to compare with the state-of-the-art detectors.