Solid-state reaction synthesis of two-dimensional CuGaSe₂ nanosheets for high performance photodetectors

CuGaSe₂ is an important non-layered I–III–VI₂ compound with superior optical properties. In this work, monocrystal two-dimensional (2D) CuGaSe₂ nanosheets were successfully synthesized via a simple solid-state reaction. The electronic and optoelectronic properties of photodetectors based on 2D CuGaSe₂ nanosheets were investigated for the first time. 2D CuGaSe₂ FETs present a typical p-type conductance behaviour, and photodetectors based on 2D CuGaSe₂ show a sensitive response to the UV-visible spectrum. Under 490 nm light illumination, the responsivity and detectivity of photodetectors are as high as 103 AW⁻¹ and 8 × 10¹¹ Jones, respectively. Our results offer a new opportunity to use 2D CuGaSe₂ nanosheets for future nano-optoelectronic devices.