Two-Dimensional Nonlayered CuInSe₂ Nanosheets for High-Performance Photodetectors

CuInSe2 has attracted great attention because of its superior optical properties, such as high optical absorption coefficient and direct-band-gap structure (1.1 eV). In this letter, for the first time, high-photoresponse-performance two-dimensional (2D) nonlayered CuInSe2 nanosheets were demonstrated. 2D CuInSe2 nanosheets showed typical p-type semiconducting transport behavior with a high-field-effect mobility of 180 cm2 V–1 s–1. Photodetectors based on 2D CuInSe2 were fabricated and showed a high response to the UV–visible spectral range (254–700 nm). The photoresponsivity and detectivity of 2D CuInSe2 photodetectors were calculated as 1900 A W–1 and 7 × 1011 Jones under 700 nm light illumination, respectively. Our results open a pathway for 2D nonlayered CuInSe2 nanosheet applications in future photodetection and photovoltaic devices.