Influence of thin film thickness of working electrodes on photovoltaic characteristics of dye-sensitized solar cells

This paper presents the study of the influence of thin film thickness of working electrodes on the photovoltaic characteristics of dye-sensitized solar cells. Titanium dioxide (TiO2) thin films, with the thickness from 7.67 to 24.3 μm, were used to fabricate the working electrodes of dye-sensitized solar cells (DSSCs). A TiO2 film was coated on a fluorine-doped tin oxide (FTO) conductive glass substrate and then sintered in a high-temperature furnace. On the other hand, platinum (Pt) solution was coated onto an FTO substrate for the fabrication of the counter electrode of a DSSC. The working electrode immersed in a dye, the counter electrode, and the electrolyte were assembled to complete a sandwich-structure DSSC. The material analysis of the TiO2 films of DSSCs was carried out by scanning electron microscopy (SEM) and ultraviolet-visible (UV-Vis) spectroscopy, while the photovoltaic characteristics of DSSCs were measured by an AM-1.5 sunlight simulator. The light transmittance characteristics of the TiO2 working electrode depend on the TiO2 film thickness. The thin film thickness of the working electrode also affects the light absorption of a dye and results in the photovoltaic characteristics of the DSSC, including open-circuited voltage (VOC), short-circuited current density (JSC), fill factor, and photovoltaic conversion efficiency.