Y-Type Titanyl Phthalocyanine Nanoparticle and Hollow ZnS Nanotube Heterojunctions with Cavity Enhancement Effect for UV–Vis–NIR Photodetectors

UV–vis–NIR photodetectors are of great importance to extensive applications, while they are limited by the low photon utilization and narrow light response range inherent in a single material. To overcome these limitations, we propose the construction of heterojunction photosensitive materials featuring a hollow structure. In this study, Y-type titanylphthalocyanine nanoparticles (Y-TiOPc NPs) and hollow ZnS nanotubes (ZnS NTs) are employed to fabricate a bulk heterojunction photosensitive material (Y-TiOPc NPs:ZnS NTs). This composite material exhibits a significant cavity enhancement effect, resulting from multiple light reflections and outstanding light absorption spanning from 365 to 1060 nm. The photodetector based on Y-TiOPc NPs:ZnS NTs (referred to as Y:ZT-PD) demonstrates remarkable photodetection capabilities, including photomultiplication phenomena. Specifically, it achieves a high external quantum efficiency of 24042%, an impressive photoresponsivity (R) of 101967 mA/W, and an excellent specific detectivity (D*) of 1.56 × 1012 Jones at 0.01 mW/cm2. Additionally, the multiperiod time-resolved photocurrent response curves exhibit rapid and stable responses across different wavelengths. Characterization results indicate that these exceptional performances primarily arise from the cavity enhancement effect of ZnS NTs and the hole-injection effect resulting from interfacial trapped electrons. Consequently, the outstanding performance, coupled with the broad spectral range and stability, positions the hollow bulk heterojunction as a promising material for the next generation of broadband photodetectors.