Low-temperature sintering of TiO2 colloids:: Application to flexible dye-sensitized solar cells

Colloidal TiO2 films have been prepared in a manner suitable for use with flexible substrates. Sol-gel particles were sintered under various conditions of temperature and initial presence/absence of organic surfactants. The physicochemical properties of the resulting films are reported. Independent of the sintering temperature, films that did not initially contain organic surfactants adhered more strongly to the underlying F:SnO2 substrate. The amount of sensitizing dyes adsorbed by a film is also sensitive to the initial presence or absence of organic surfactants and to the sintering temperature. Used as a dye-sensitized anode in photoelectrochemical cells, an open-circuit photovoltage of 647 mV and a short-circuit photocurrent density of 2 mA/cm(2) were obtained for 1 mu m thick TiO2 films sintered at 100 degrees C; normalized to the same thickness, similar results were obtained with films initially containing surfactant and sintered at 450 degrees C.