An efficient method to boost the short-circuit current of quantum-dot-sensitized solar cells

Abstract

According to the Marcus theory, the driving force for the transfer of photogenerated electrons from quantum dots (QDs) to oxide nanocrystals depends on the energy difference of the system. In this study, an efficient driving force for the transfer of photoinduced charge—inner electric field effects—was suggested. The inner electric field was introduced from the p-NiO/n-ZnO heterojunction, which was formed by the in situ deposition of NiO on the ZnO nanosheet/nanorod film surface. Photoluminescence spectra revealed that the photogenerated charge carriers can be efficiently separated at the interface of p-NiO/n-ZnO. The QD-sensitized solar cells (QDSCs) assembled with the p-NiO/n-ZnO photoanodes exhibited considerably higher JSC compared to those fabricated with ZnO photoanodes, indicating that the formation of a p–n junction at the photoanode surface is an efficient strategy to boost the short-circuit current of QDSCs.