Particle Size and Crystallinity Dependent Electron Injection in Fluorescein 27-Sensitized\nTiO₂ Films

Abstract

Influence of processing parameters, such as autoclaving and firing temperature, on the optical properties of\nnanocrystalline anatase TiO₂ film and on the process of electron injection from the dye fluorescein 27 to the\nas-prepared films is studied. Transmission electron microscopy and steady-state and time-resolved femtosecond\nspectroscopy measurements indicate that the larger the TiO₂ particle and the better its overall crystallinity,\nthe faster the process of electron injection. Unraveling factors that control the properties of the sub-20-nm\nsized semiconductor particles, and by this the electron injection to them, is important for understanding the\nprocess of interfacial electron transfer from the dye to the semiconductor, as well as future optimization of\nthe function of the photoelectrochemical cell based on dye-sensitized TiO₂ films.