Enhanced photoelectric properties of CdSe/graphene composites with various contents of graphene

CdSe/graphene composites with different contents of graphene were prepared by the solvothermal method. The composites were characterized by X-ray diffraction, scanning electron microscope and further investigated by transient photocurrent responses and electrochemical impedance spectroscopy. Compared with pure CdSe particles, CdSe/graphene composites show improved photocurrent responses and decreased electron-transfer resistance due to the presence of graphene, which acts as an electron collector and transporter as well as the supporting matrix for CdSe particles. The composites were synthesized by varying the graphene content from 0.5 wt% to 6 wt%, which has been experienced to exert great influence on the photoelectric characteristics of CdSe/graphene composites. A higher photocurrent density and smaller arc radius can be observed for 0.5% CdSe/graphene composites.