Preparation of dye sensitized solar cell by using supercritical carbon dioxide drying

Abstract

Dye-sensitized solar cells (DSSC) derived from TiO2 aerogel film electrodes were fabricated. TiO2 aerogels were obtained by using sol–gel method and supercritical carbon dioxide (sc-CO2) drying. First, TiO2 wet gels were obtained by sol-gel method. Then, the solvents in the TiO2 wet gels were replaced by acetone. The TiO2 aerogels were obtained by using sc-CO2 drying from the TiO2 wet gels. The conditions of sc-CO2 drying were at 313, 323K and 7.8–15.5MPa. The electrodes with TiO2 aerogel films were obtained by deposition of the aerogels on glass substrates. The electrodes with TiO2 aerogel films and a commercial particle film of various thickness were obtained by repetitive coatings and calcinations. The amount of dye adsorbed on the TiO2 films with sc-CO2 drying was higher than that of commercial particle film. The amount of dye adsorbed on the TiO2 films increased with increasing surface area of the TiO2 film. DSSCs were assembled by using the TiO2 aerogel film electrodes and their current–voltage performance was measured. The power performance of DSSC made by supercritical drying was higher than that of commercial particles. The DSSC with the film electrode made at 313K and 15.5MPa showed the best power performance (Jsc=7.30mA/cm2, Voc=772mV, η=3.28%).