Band engineering to suppress dark current in self-powered solar-blind photodetectors for optoelectronics in harsh environments
Phys. Rev. Applied 24, 064043 – Published 15 December, 2025
DOI: https://doi.org/10.1103/mnx1-t34v
Abstract
Solar-blind ultraviolet (UV) communication has gained significant attention due to its low background noise, non-line-of-sight transmission, and high security. Achieving efficient solar-blind UV communication requires photodetectors with high sensitivity to weak solar-blind UV signals, low dark current, and excellent stability. In this study, an all-inorganic β- three-layer heterostructure was developed for self-powered solar-blind UV photodetectors. The introduction of a electron-blocking layer effectively suppressed thermal carrier transport in the dark by creating a high conduction-band barrier, significantly reducing dark current. Compared to traditional β-p- two-layer heterojunctions, the dark current of the β- photodetector is reduced by factors of 5.9 at 0 V and 19.2 at 20 V, respectively, along with a 77.6-fold and 5.9-fold increase in the photocurrent-to-dark current ratio. The device demonstrated a responsivity of 0.27 A/W under 254-nm illumination with a light power of 100 nW/ and robust stability across extreme temperatures (−170 °C to 100 °C). These results highlight the potential of the β--based photodetector for high-performance solar-blind UV communication systems.