Direct growth Bi2OSe nanosheets on SiO/Si substrate for high-performance and broadband photodetector.

BiOSe, 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 SrTiOsubstrates with lattice matching are commonly used for the growth of high-quality 2D BiOSe. Although 2D BiOSe 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 BiSeas the evaporation source and oxygen reaction to directly grow BiOSe nanosheets on Si substrate through a conventional chemical vapor deposition method. The photodetector based on the BiOSe nanosheets on Si substrate demonstrates outstanding optoelectronics performance with a responsivity of 379 A W, detectivity of 2.9 × 10Jones, 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 BiOSe nanosheets for high-performance and broadband photodetector applications.