Photocurrent observed in dye-doped titania gel

Thin titania gel films dispersing fluorescein were prepared by the sol–gel method and treated with steam in order to promote crystal growth of the titania particles. The properties of photo-electric energy conversion of the films were investigated by spectroscopic and electric measurements. Photocurrent action spectra of the fluorescein-doped films agreed with the absorption spectra of the dianion of the dye. The photocurrent increased with an increase in the duration of the steam-treatment of the gel films. The growth and crystallization of the titania particles by steam-treatment improved their electric conductivity.