CuInSe2 nanocrystals/CdS quantum dots/ZnO nanowire arrays heterojunction for photovoltaic applications

A low-cost and novel nanostructure heterojunction, which consists of the CuInSe2 nanocrystals (NCs)/CdS quantum dots (QDs)/ZnO nanowire (NW) arrays, is fabricated for photovoltaic applications. The ZnO NW arrays with high transmittance are used as a highly efficient channel for rapid collection of the carriers to reduce the charge recombination, as well as to increase the contact area of the heterojunction. The p-type CuInSe2 NCs are synthesized by a solvothermal method and then deposited on the CdS QDs coated ZnO NW arrays by an electrophoretic deposition technique. Results indicate that such a heterojunction configuration not only has high absorption for the incident light in the visible region but also can reduce the leakage current. A photovoltaic efficiency of the heterojunction is doubled as compared with that of the CuInSe2 NCs/CdS QDs/ZnO thin film photovoltaic devices.

highlights
► A novel heterojunction, CuInSe2 NCs/CdS QDs/ZnO NW arrays, is fabricated.
► The ZnO NW arrays serve as a rapid charge transfer channel.
► The ZnO NW arrays can enlarge the contact area of the heterojunction.
► The CuInSe2 NCs are deposited on CdS QDs/ZnO NW arrays by the electrophoretic method.