Fabrication of two Se/CsPbBr(3) heterojunctions structures for self-powered UV–visible photodetectors

It has been a universal route for enhanced photoelectric performance in photodetectors by constructing a heterojunction that is conductive for suppressing recombination of photogenerated carriers and promoting collection efficiency, and probably producing self-powered capability. However, the dependence of the built-in electric field distributions created by the heterojunction on photodetector performance has rarely been investigated. Herein, two kinds of self-powered UV–visible photodetectors with different device architectures based on single Se wire and CsPbBr(3) particles are facilely fabricated and compared. It is found that both the two photodetectors show excellent self-powered operating properties, fast response and binary response. However, due to the different distributions of built-in electric field caused by device architectures, it yields a significant photovoltaic voltage distinction and different responsivity and detectivity spectra for the Se/CsPbBr(3) photodetectors. These results are conductive to guide the design of self-powered heterojunction photodetectors by regulating the built-in electric field distributions.