Heterojunction is regarded as a crucial step toward realizing high-performance devices,particularly,forming gradient energy band between heterojunctions benefits self-powered photodetectors.There-fore,in this paper,the synthesis of CsPbI3 nanorods(NRs)and its application as the interfacial layer in high-performance,all-solution-processed self-powered photodetectors are presented.For the bilayer photodetector ITO/ZnO(100 nm)/PbS-TBAI(150 nm)/Au,a responsivity of 3.6 A/W with a specific detec-tivity of 9.8×1012 Jones was obtained under 0.1 mW/cm2 white light illumination at zero bias(i.e.in self-powered mode).Meanwhile,the photocurrent was enhanced to an On/Off current ratio of 10s at zero bias with an open circuit voltage of 0.53 V for trilayer photodetector ITO/ZnO(100 nm)/PbS-TBAI(150 nm)/CsPbI3(250 nm)/Au,in which the CsPbI3 NRs layer works as the interfacial layer.As a result,a specific detectivity of 4.5×1013 Jones with a responsivity of 11.12 A/W was obtained under 0.1 mW/cm2 white light illumination,as well as the rising/decaying time of 0.57 s/0.41 s with excellent stability and reproducibility upto four weeks in air.The enhanced-performance is ascribed to the mis-match bandgap between PbS-TBAI/CsPbI3 interface,which can suppress the carrier recombination and provide efficient transport passages for charge carriers.Thus,it provides a feasible and efficient method for high-performance photodetectors.