Horizontally Self‐Standing Growth of Bi2O2Se Achieving Optimal Optoelectric Properties

Abstract Air‐stable 2D Bi 2 O 2 Se material with high carrier mobility appears as a promising semiconductor platform for future micro/nanoelectronics and optoelectronics. Like most 2D materials, Bi 2 O 2 Se 2D nanostructures normally form on atomically flat mica substrates, in which undesirable defects and structural damage from the subsequent transfer process will largely degrade their photoelectronic performance. Here, a new synthesis route involving successive kinetic and thermodynamic processes is proposed to achieve horizontally self‐standing Bi 2 O 2 Se nanostructures on SiO 2 /Si substrates. Fewer defects and avoidance of transfer procedure involving corrosive solvents ensure the integrity of the intrinsic lattice and band structures in Bi 2 O 2 Se nanostructures. In contrast to flat structures grown on mica, it displays reduced dark current and improved photoresponse performance (on–off ratio, photoresponsivity, response time, and detectivity). These results indicate a new potential in high‐quality 2D electronic nanostructures with optimal optoelectronic functionality.