ELECTROCHEMICAL PROPERTIES OF SURFACE MODIFIED SPRAYED SNO2 FILMS

Photoinduced deposition of platinum onto sprayed SnO2 thin films is studied under open circuit conditions and continuous exposure to intense mu-nu radiation provided by a xenon lamp. The amount of deposited Pt is measured by Energy Dispersive X-ray Analysis and Rutherford Back Scattering as a function of time of exposure. It is found to be dependent on the film substrate, which is either a glass sheet or a n-type silicon (100) wafer. The deposition rate is five times higher with Si substrate than with glass substrate. It is observed that metal deposition is localized in the spot area only for SnO2/glass system. These results are explained by considering electron injection from Si to the conduction band of SnO2. The application of discontinuous metal deposition in improving transfer kinetics is demonstrated in the case of transparent electrodes and that of heterojunction photoelectrodes.