High-performance solar-blind ultraviolet photodetector based on electrospun TiO₂-ZnTiO₃ heterojunction nanowires

High-performance solar-blind UV (ultraviolet) photodetectors (PDs) based on low-dimension semiconducting nanostructures with high sensitivity, excellent cycle stability, and the ability to operate in harsh environments are critical for solar observations, space communication, UV astronomy, and missile tracking. In this study, TiO₂-ZnTiO₃ heterojunction nanowire-based PDs are successfully developed and used to detect solar-blind UV light. A photoconductive analysis indicates that the fabricated PDs are sensitive to UV illumination, with high sensitivity, good stability, and high reproducibility. Further analysis indicates that the rich existence of grain boundaries within the TiO₂-ZnTiO₃ nanowire can greatly decrease the dark current and recombination of the electron-hole pairs and thereby significantly increase the device’s photosensitivity, spectra responsivity (1.1 × 10⁶), and external quantum efficiency (4.3 × 10⁸ %). Moreover, the PDs exhibit good photodetective performance with fast photoresponse and recovery and excellent thermal stability at temperatures as high as 175 °C. According to these results, TiO₂-ZnTiO₃ heterojunction nanowires exhibit great potential for applications in high-performance optical electronics and PDs, particularly next-generation photodetectors with the ability to operate in harsh environments. [Figure not available: see fulltext.]