Columnar rutile TiO2 based dye-sensitized solar cells by radio-frequency magnetron sputtering

Columnar-structured rutile TiO2 film with a thickness of 1.4 μm is prepared using the radio-frequency (RF) magnetron sputtering technique, for application in dye-sensitized solar cells (DSSCs). Pure rutile TiO2 films are fabricated by controlling the substrate temperature during sputtering and using a substrate with a rough surface morphology. Successive substrate heating to 623 K induces the growth of a rutile TiO2 film that has a specific direction in the (1 1 0) plane, which results in a decrease in the average grain size. This causes in an increase of dye uptake and thereby contributes to enhancement of the photocurrent in the DSSC.