Fabrication of Dye-Sensitized Solar Cell (DSSC) Using Different Particle Sizes of TiO₂ Deposited via Nano-Particle Deposition System (NPDS)

TiO₂ layers were fabricated using a nano-particle deposition system (NPDS) on transparent conductive oxide (TCO) glass for dye sensitized solar cells (DSSCs). Conventionally, TiO₂ paste for working electrodes has been fabricated using paste type methods. The fabricated paste composed of a mixture of nano-sized TiO₂ powders, binders and solutions is then painted on TCO glass. After drying, the TiO₂ layer on TCO glass is sintered to make a path for electron transfer. TiO₂ layers formed by this paste type method require numerous steps, which can be time consuming. In this study, TiO₂ powders were sprayed directly on TCO glass using NPDS in order to simplify the fabrication steps. To improve porosity and produce scattering layers, commercial nanocrystalline TiO₂ powders with different sizes were alternately deposited. Moreover, powders with different sizes were mixed and deposited on the TCO glass. The results indicate that the DSSCs with a TiO₂ layer composed of different particle sizes had better cell performance than the cells assembled with single-sized TiO₂ particles. Therefore, this study shows that a dry TiO₂ coating process is possible for DSSC fabrication to improve its cell efficiencies, and this method can easily be applied on flexible substrates since NPDS is a room-temperature deposition process.