A High-Performance All-Carbon Diamond Pixel Solar-Blind Detector with In Situ Converted Graphene Electrodes

Solar-blind ultraviolet detectors, known for their low background noise and high sensitivity, have garnered significant attention in various applications such as space communications, ozone layer monitoring, guidance applications, and flame detection. Pixel photodetectors, as the cornerstone of imaging technology in this field, have become a focal point of research in recent years. In this work, a solar-blind photodetector with a 6 × 6 planar pixel array was fabricated on single-crystal diamond substrate, utilizing in situ conversed graphene electrodes. The graphene electrodes achieved exceptional Ohmic contact with the diamond surface, boasting a remarkably low specific contact resistance of 6.73 × 10^-5 Ω·cm². The diamond pixel detector exhibited high performance consistency with an ultra-low dark current ranging from 10^-11 to 10^-12 A and a photocurrent of 10^-8~10^-9 A under 222 nm illumination with a bias of 10 V. This work not only demonstrates the feasibility of fabricating all-carbon solar-blind photodetectors on diamond but also highlights their potential for achieving high spatial resolution in solar-blind image detection.