A Vertical Structured Solar-blind Ultraviolet Photodetector Based on Carbon Dots/Graphene.

Compared with infrared, solar-blind ultraviolet (UV) has the advantage of extremely low background noise, which is prospective in the field of photodetection. A vertical structure has attracted our attention due to the short channel length and the high carrier mobility. Meanwhile, carbon quantum dots (CDs) are a promising photosensitive layer material, while graphene shows excellent photoelectric properties after binding to CDs. This paper builds a vertical structured solar-blind UV PD, with graphene used as the transparent electrode, CDs film used as the photosensitive layer, and aluminum film used as the source and drain contacts. The device exhibits responsivity of 375.5 mA/W, normalized detectivity of 9.36x10(8) Jones and on/off ratio of 11.2 at -5V drain-source bias voltage and 0V gate voltage under the illumination of 1.5mW/cm2 by 254 nm wavelength. The results show that our PD has excellent photoelectric performance.