Energy & Fuels, Vol.25, No.3, 1168-1172, 2011
Effects of Ethanol on Optimizing Porous Films of Dye-Sensitized Solar Cells
Solvent, dispersant, and surfactant play different roles in forming porous films of dye-sensitized cells (DSSCs), L when they are added into the paste. We investigate the influence of ethanol, acetyladetone, and Triton-X100 on the photoelectrode of DSSCs with orthogonal array design experiments. Stereoscopic morphologies of photoelectrodes scanned with atomic force microscopy (AFM) show that decreasing the amount of ethanol in TiO2 paste results in forming a more compact structure of the photoelectrode for DSSCs. The TiO2 photoeletrode made with 2.5 g of TiO2 nanoparticle powder dissolved in 20 mL of ethanol presents lower root-mean-square (rms) roughness calculated from AFM, and its corresponding performance in DSSCs shows higher photoelectric conversion efficiency, while the effects of acetylacetone and Triton-X100 on the performance of DSSCs are not very apparent. Optimized photoelectrode dyed with N719 shows increased light absorption. This may result from adsorbing more amount of dye on a larger inner area of the porous photoelectrode. We find that the DSSC with the photoelectrode made from 2.5 g of TiO2 nanoparticle powder dissolved in 20 mL of ethanol containing 0.8 mL of acetylacetone and 0.6 mL of Triton-X100 shows a I large increase in short-circuit current density (J(sc)) and a little improvement in open-circuit voltage (V-oc). At the optimized point, photoelectric conversion efficiency of 6.1% is obtained.