Ultrathin Bi₂O_{<bold>2</bold>}Se/Si Heterojunction Photodetector with Tunneling Oxide Passivation for Enhanced Optoelectronic Performance

Abstract

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 (similar to 22.3 nA/cm(2)), a high on/off ratio (similar to 8 x 10(6)), 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.