Ultrathin Bi₂OSe/Si Heterojunction Photodetector with Tunneling Oxide Passivation for Enhanced Optoelectronic...

Two-dimensional (2D) materials have garnered significant attention for next-generation optoelectronic devices due to their exceptional physical properties. This study introduces a high-performance ultrathin Bi₂O₂Se/Si heterojunction photodetector with tunneling oxide passivation, fabricated using a transfer-free pulsed laser deposition method. The Bi₂O₂Se layer exhibits strong air stability and compatibility for practical applications. By incorporating a thin SiO₂ tunneling layer, the heterostructure achieves a low dark current (∼22.3 nA/cm²), a high on/off ratio (∼8 × 10⁶), and a responsivity of 23.0 A/W. Compared to traditional CdS/Si devices, this photodetector demonstrates superior performance, including faster response time and higher stability. These findings underscore the potential of Bi₂O₂Se/Si heterostructures for advanced photonic and optoelectronic applications.