Graphene ultraviolet photodetector enhanced by a plasmon local field with a morphologically controlled flower-like silver structure

Graphene has received significant attention in the field of photodetection due to its excellent photoelectric properties. However, the inherently low-absorption rate hinders its utilization. In this work, we present a graphene hybrid device by introducing morphologically controlled flower-like silver nanoparticles (Ag NFs) for ultraviolet (UV) detection. The experimental results indicate that the photo-response of the graphene-based device transforms from negative photoconductivity (NPC) to positive photoconductivity (PPC) after the incorporation of Ag NFs benefiting from plasma-enhanced light trapping, highly efficient hot-electron injection and carrier transport. Besides, we observed the varied photo-response of graphene hybridized with different morphology-controlled plasmonic nanostructures. Among them, Ag NFs with a perfect flower-like structure showed a superior plasma coupling effect, and the graphene/Ag NFs hybrid device showed a high specific detection rate of 4.6×10 9 Jones at a low voltage of 0.1 V under 270 nm UV irradiation. This study provides a facile and effective strategy for plasma-enhanced photodetection performance of graphene-based devices.