Intersubunit Electron Transfer (IET) in Quantum Dots/Graphene Complex: What Features Does IET Endow the Complex with?

First principles calculations of quantum dots (QDs)/graphene (QDs/GR) hybrid nanomaterials were performed to investigate the interfacial electron hole separation process at the atomistic level for verifying the tentative mechanism and unveiling the functionalities endowed by the intersubunit electron transfer. Our calculated results unveil the intersubunit electron transfer mechanism of QDs/GR nanomaterials: upon visible light adsorption, the ground electron of CdS QD in nanomaterials is first promoted to the excitated state, which then injects into the conduction band of graphene and transports along graphene layer through pi* orbitals to achieve interfacial electron hole separation. Adiabatic and nonadiabatic methods are used to estimate the electron transfer time at the heterogeneous interface from CdS QD to graphene. Our findings suggest a new route to facilitate the design of QDs@GR based nanodevices.