High efficiency ultraviolet photovoltaic cells based on ZnO–C60 core–shell QDs with organic–inorganic multilayer structure

We report on the successful conjugation of C60 molecules on the surface of ZnO quantum dots (QDs) and their application in multi-layer structured ultraviolet (UV) photovoltaic (PV) devices. In situgrowth of C60 on the surface of ZnO QDs with a core–shell structure was realized via a mild solution-process method, which resulted in an improvement in photo-induced charge separation and transport of carriers to the collecting electrodes in a fabricated device. The conjugation of the C60 with ZnO QDs leads to a PL quenching of about 99.8%, which can be attributed to an efficient transfer of photo-induced electrons from the ZnO QDs to the C60 through a Zn–O–C chemical bonding. UV PV cells with ZnO–C60 core–shell QDs as an active layer and fabricated through an all layer simple chemical method exhibit high power conversion efficiency as much as about 3.02%.