Dependence of electron transport in nanocrystalline TiO{sub}2 films sensitized with [NBu{sub}4]{sub}2[Ru(Htcterpy)(NCS){sub}3] ([NBu{sub}4]{sup}+ = tetrabutylammonium cation; H{sub}3tcterpy = 4,4',4''-tricarboxy-2,4:2',4':2''-terpyridine) on the

摘要

Nanocrystalline TiO{sub}2 colloids were prepared by hydrothermalization. The porosity and the size distribution of the particles increase with a longer hydrothermalization reaction period. The particle size decreases with lower reaction temperature. Electron transport in nanocrystalline TiO{sub}2 film electrodes sensitized with [NBu{sub}4]{sub}2[Ru(Htcterpy)(NCS){sub}3] ([NBu{sub}4]{sup}+ = tetrabutylammonium cation; H{sub}3tcterpy = 4,4',4''-tricarboxy-2,4:2',4':2''-terpyridine) (black dye) was investigated from the standpoint of TiO2 particle properties such as particle size, size distribution, and porosity. When the size distribution and the porosity were comparable, the electron lifetime (τ{sub}(rec)) increased and the electron diffusion coefficient (D) decreased at smaller particle sizes. The value of D decreased when the porosity increased. Large differences in the diffusion length (L = (Dτ{sub}(rec)){sup}(1/2)) among the TiO{sub}2 films were observed. However, J{sub}(SC) did not depend on L, Thus, we conclude that the J{sub}(sc) values were more effectively influenced by the absorption coefficient (a) than by L.