Abstract:

Two-dimensional (2D) ternary wide-bandgap semiconducting materials have great potential in power device, flexible electronic device, short-wavelength light emitting diodes (LEDs) and photodetectors due to the controllable bandgap, strong light-material interaction, and controlled freedom degree of stoichiometry variation. However, it is still a great challenge to precisely control the growth of high-quality 2D ternary wide-bandgap semiconducting materials due to the variety of components, which hinders their development for practical applications. In this work, high-quality 2D ternary bismuth oxybromide single-crystal nanosheets with a high yield were prepared by space-confined chemical vapor deposition (CVD) method. The devices based on 2D ultrathin BiOBr single-crystal nanoflakes show a high UV detecting performance including low dark current (I_dark) of 1.46 pA and high responsivity (R), external quantum efficiency (EQE) and detectivity (D*) of 14.96 A W^-1, 5460%, and 5.74 × 10 ¹⁰ Jones, respectively, as well as fast response process (τ_rise =80 ms, τ_decay =40 ms). The excellent UV performance can be ascribed to the photogating effect by trapped states, which endow it with great potential for high-performance UV detectors.

Key words: Bismuth oxybromide, CVD, 2D, UV