Fabrication and Characterization of Photoelectrode Thin Films with Different Morphologies of TiO₂ Nanoparticles for Dye-Sensitized Solar Cells

This study deals with the fabrication of three different morphologies of TiO₂ nanoparticles to fabricate two-layer photoelectrode thin film for dye-sensitized solar cells (DSSC). The four different TiO₂ morphologies are titania nanotubes (Tnt), TiO₂ nanoparticles (H220), TiO₂ nanoparticle (SP) and commercial DP-25 nanoparticles (P-25). To prepare the thin films of the photoelectrodes, the first layer is coated by H220 TiO₂ nanoparticles, and the second is coated by 3 kinds of materials optimally proportionally mixed – P25, SP and Tnt. The photoelectric conversion efficiency of DSSCs with photoelectrodes fabricated using H220 reached 6.31%. Finally, the TiO₂ nanaomaterials with four different morphologies were used to prepare a two layer photoelectrode with the structure of H220/P25-Tnt-SP which was combined with a Pt counter electrode to assemble DSSCs. These DSSCs had photoelectric conversion efficiencies of as high as 7.47%.