Highly Crystalline Bi2O2Se Nanosheet Growth by Dual-Source Independent Control Technology for Photodetector

As an emerging 2D-layered semiconductor material, the Bi2O2Se nanosheet has shown great application potential in the field of electronics and optoelectronics due to its high carrier mobility, superior air stability, and tunable bandgap. However, the mechanism of controllable synthesis of Bi2O2Se nanosheets is still unclear, and further basic research and applications are urgently needed in the field of photovoltaics. In this paper, Bi2O2Se nanosheets were prepared based on the "dual-source independent control" method, and photodetectors were demonstrated on Si/SiO2. The device has a mobility of 258.6 cm2 V–1 s–1, responsivity of 8030 A/W at 532 nm (0.32 mW/cm2), and detectivity of 1.972 × 1011 Jones, and the detector obtains highly stable and recoverable properties with multiple laser switches. The modulation mechanism of Bi2O2Se-based photodetectors is then explored based on the I–V characteristics of photodetectors and photoconductivity effect solutions.