High-performance, flexible graphene/ultra-thin silicon ultra-violet image sensor

Abstract

We report a high-performance graphene/ultra-thin silicon metal-semiconductor-metal (MSM) ultraviolet (UV) photodetector, which benefits from the mechanical flexibility and high-percentage visible light rejection of ultra-thin silicon. In the near- and mid-UV spectral region, the proposed UV photodetector exhibits high photo-responsivity (0.47 A/W @ 3 V), fast time response (1 ps), high specific detectivity (2.5 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</sup> Jones), and UV/Vis rejection ratio of about 100, comparable to the state-of-the-art GaN and SiC Schottky photodetectors. The photodetector is semi-transparent, and its performance is stable after 1,000 bending cycles. Furthermore, we demonstrated UV imaging by replacing CCD array with the proposed graphene/silicon image sensor in a custom-designed digital camera.