Photoresponse mechanisms of a graphene-based quantum-dot monolayer structure

Hybrid structures of graphene sheets based quantum dots (QDs) are produced via Langmuir–Blodgett (LB) technique. Morphology of the structures produced is investigated by atomic force microscopy (AFM) and scanning electron microscopy (SEM). Two types of hybrid structures are prepared from graphene covered by sublayers of CdSe/CdS/ZnS and CdSe/ZnS QDs. Photocurrent properties are studied by current–voltage characteristics (CVCs) in the dark and while exposed to visible light and ultraviolet (UV) light with an excitation wavelength of 365 nm. The rise and decay times of graphene and QDs after UV illumination are estimated.