Low-Temperature Chemical Sintered TiO2 Photoanodes Based on a Binary Liquid Mixture for Flexible Dye-Sensitized Solar Cells

Abstract

A chemically sintered and binder-free paste of TiO 2 nanoparticles (NPs) was prepared using a binary-liquid mixture of 1-octanol and CCl 4 . The 1:1 (v/v) complex of CCl 4 and 1-octanol easily interacted chemically with the TiO 2 NPs and induced the formation of a highly viscous paste. The as-prepared binary-liquid paste ( P BL )-based TiO 2 film exhibited the complete removal of the binary-liquid and residuals with the subsequent low-temperature sintering (~150ºC) and UV-O 3 treatment. This facilitated the fabrication of TiO 2 photoanodes for flexible dye-sensitized solar cells ( f -DSSCs). For comparison pur-poses, pure 1-octanol-based TiO 2 paste ( P O ) with moderate viscosity was prepared. The P BL -based TiO 2 film exhibited strong adhesion and high mechanical stability with the conducting oxide coated glass and plastic substrates compared to the P O -based film. The corresponding low-temperature sintered P BL -based f -DSSC showed a power conversion efficiency (PCE) of 3.5%, while it was 2.0% for P O -based f -DSSC. The P BL - based low- and high-temperature (500ºC) sintered glass-based rigid DSSCs exhibited the PCE of 6.0 and 6.3%, respectively, while this value was 7.1% for a 500ºC sintered rigid DSSC based on a commercial (or conventional) paste.