Effects of release agents on the film morphology of TiO2 photoanodes for FDSSCs by the roll-to-roll method

Flexible dye-sensitized solar cells (FDSSCs) are dye-sensitized thin-film solar cells constructed on flexible substrate with the advantages of eco-friendly, ease of fabrication, low cost and light weight. FDSSCs exhibit extensive application prospect. Herein, FDSSCs were constructed by the roll-to-roll method using terpineol and silicone oil as the release agent. Three-dimensional profile measurement is taken directly on nanocrystalline-TiO2 photoanodes. The phase composition and surface micro-morphology indicate that relatively large grain sizes and uniform surface of TiO2 particles are obtained. A layer of amorphous SiO2 exists on the nanocrystalline-TiO2 photoanode owing to the release agent (silicon oil), which hinders electrons to travel, thus the photoelectric conversion efficiency is low. However, nanocrystalline-TiO2 photoanodes with uniform particles, good density and high porosity are achieved by using the release agent of terpineol, and the energy conversion efficiency of 2.97% was obtained.