High-performance UV-Vis-NIR photomultiplier detectors assisted by interfacial trapped-electrons

Abstract

UV–Vis–NIR photodetectors play a crucial role in numerous scientific and commercial applications. It is a great challenge to realize UV–Vis–NIR photodetectors due to the limited photoresponse range of single materials, especially photomultiplication type detectors. In this work, a bulk heterojunction strategy is used to construct Y-TiOPc NP and ZnS NR photosensitive materials (Y-TiOPc:ZnS) with outstanding light absorption in the range of 365 nm to 940 nm. The photodetector based on Y-TiOPc:ZnS (YZ-PD) exhibits an obvious photomultiplication phenomenon and excellent photodetection performance with the maximum external quantum efficiency (EQE) of 2985.5% and a photoresponsivity (R) of 8782 mA W⁻¹ under a low-intensity of 0.01 mW cm⁻². Moreover, the photocurrent response curves are all prompt, steady and reproducible during repeated on/off cycles under different exposure wavelengths. Such high performances can be attributed to the complementary absorption spectra of Y-TiOPc NPs and ZnS NRs, the improvement in carrier generation efficiency, separation efficiency, and transmission rate caused by bulk heterojunctions, and the enhancement of external hole tunneling injection efficiency assisted by interfacial trapped electrons. This work demonstrates that the construction of bulk heterojunctions by incorporating UV photosensitive materials and Vis–NIR photosensitive materials has immense potential to prepare highly sensitive broadband photomultiplier detectors, which may inspire further research on high-performance full spectrum photodetectors.