PREPARATION OF NANOCRYSTALLINE ZnO/TiO2 FILM AND ITS APPLICATION TO DYE-SENSITIZED SOLAR CELLS

Abstract

Dye-sensitized solar cells (DSSCs) were built by using ZnO/TiO2 films as electrodes consisting of ZnO nanorod arrays coated with TiO2 nanoparticles (NPs) in sol or slurry form prepared by sol–gel methods. The addition of TiO2 sol to ZnO arrays resulted in an improvement of cell performance, but the cell efficiency was not high. The cell efficiency was more improved by coating of ZnO arrays with TiO2 slurry. The tetraethylammonium hydroxide surfactant was effective to control TiO2 NPs suspension between sol and slurry. The penetration of TiO2 sol or slurry into ZnO array was important, especially in the long nanorod array. The cell performance of ZnO/TiO2 electrode increased more by TiO2 slurry than by TiO2 sol because TiO2 sol shrank more during calcination.