On the photoelectrochemical properties of TiS3 films

Preliminary results on the photoelectrochemical properties of polycrystalline TiS3 layers grown on titanium substrates are shown. At first glance, TiS3 layers are composed by needles of bluish-black colour, but scanning electron microscopy (SEM) images show rough surfaces formed by a large number of thin ribbon shaped structures. Ribbons are formed by monoclinic TiS3, as identified by X-ray diffraction patterns, with crystallite size of about 80nm. S/Ti stoichiometric ratio of 2.9 (+/- 0.1) was estimated by energy dispersive x-ray analyses. Photocurrent measurements in an aqueous solution containing SO32- ions have been taken at different bias potential under white illumination (I-ph-V curve) and under different photon energies at 0.2V(Ag+/AgCl) (photocurrent spectral response). The most significant results from these measurements are the anodic photocurrent, hinting n-type conductivity what agrees well with previously reported transport data, and the two direct transitions, at 1.1 and 1.6 eV, obtained from the photocurrent spectral response. (C) 2012 Published by Elsevier Ltd. Selection and/or peer review under responsibility of European Material Research Society (E-MRS)