The purpose of this research was to study the effects of printable TiO₂ pastes which have different solvent, composition and preparation conditions on the properties of TiO₂ electrodes and conversion efficiency. In order to form films, various printable TiO₂ pastes were prepared by changing preparation conditions and types of solvents (high/low boiling point solvents, water-based solvents). Screen-printing paste PST-18NR supplied by CCIC consists of 20nm TiO₂ particles, organic solvent and polymer. The paste could form a TiO₂ film that has an average pore diameter of 18-20 nm and a pore volume of 0.38-0.42 ml/g. The result of measuring the I-V curve of fabricated DSC which used PST-18NR (20 nm TiO₂ particles) and PST-400C (400 nm TiO₂ particles) is shown in Fig. 1. The conversion efficiency is 8.78 %.
Changing the preparation method and composition of TiO₂ paste could control the average pore diameter and pore volume of TiO₂ film. The results of measuring pore distribution of some TiO₂ films are shown in Fig. 2. Although the pore distributions were different, conversion efficiencies of these films were 6.0-6.4% using organic solvent electrolyte. In this report we will give the conversion efficiency results using other electrolytes such as ionic liquid.
Moreover, we are preparing TiO₂ pastes that consist of water or light organic solvent. We would like to discuss the properties of TiO₂ films which are made of these pastes and the effects of the solvent of TiO₂ pastes on the conversion efficiency.