Surface Engineering in SnO₂/Si for High-Performance Broadband Photodetectors

Silicon-based photodetectors are important optoelectronic devices in many fields. Many investigations have been conducted to improve the performance of silicon-based photodetectors, such as spectral responsivity and sensitivity in the ultraviolet band. In this study, we combine the surface structure engineering of silicon with wide-bandgap semiconductor SnO₂ films to realize textured Si-based heterojunction photodetectors. The obtained SnO₂/T-Si photodetectors exhibit high responsivity ranging from ultraviolet to near-infrared light. Under a bias voltage of 1 V, SnO₂/T-Si photodetectors (PDs) with an inverted pyramid texture show the best performance, and the typical responsivities to ultraviolet, visible, and near-infrared light are 0.512, 0.538, 1.88 (800 nm, 67.7 μW/cm²) A/W@1 V, respectively. The photodetectors exhibit short rise and decay times of 18.07 and 29.16 ms, respectively. Our results demonstrate that SnO₂/T-Si can serve as a high-performance broadband photodetector.