Direct growth Bi2O2Se nanosheets on SiO2/Si substrate for high-performance and broadband photodetector

Abstract Bi 2 O 2 Se, a newly emerging two-dimensional (2D) material, has attracted significant attention as a promising candidate for optoelectronics applications due to its exceptional air stability and high mobility. Generally, mica and SrTiO 3 substrates with lattice matching are commonly used for the growth of high-quality 2D Bi 2 O 2 Se. Although 2D Bi 2 O 2 Se grown on these insulating substrates can be transferred onto Si substrate to ensure compatibility with silicon-based semiconductor processes, this inevitably introduces defects and surface states that significantly compromise the performance of optoelectronic devices. Herein we employ Bi 2 Se 3 as the evaporation source and oxygen reaction to directly grow Bi 2 O 2 Se nanosheets on Si substrate through a conventional chemical vapor deposition method. The photodetector based on the Bi 2 O 2 Se nanosheets on Si substrate demonstrates outstanding optoelectronics performance with a responsivity of 379 A W −1 , detectivity of 2.9 × 10 10 Jones, and rapid response time of 0.28 ms, respectively, with 532 nm illumination. Moreover, it also exhibits a broadband photodetection capability across the visible to near-infrared range (532–1300 nm). These results suggest that the promising potential of Bi 2 O 2 Se nanosheets for high-performance and broadband photodetector applications.