Photothermal deflection spectroscopy of a powder-layer photoelectrochemical structure

Abstract
Photothermal deflection spectroscopy has been used to characterize a new photoelectrochemical (PEC) structure consisting of a thin porous layer of microscopic TiO2 or WO3 powder above a metallized substrate. For TiO2, factors affecting PEC activity such as crystal structure and degree of electronic conductivity can be correlated with their corresponding optical absorption spectra. For WO3, electronic charge transfer between powder and substrate is revealed by electrochromism in the powder under cathodic bias in acid solution.