XPS analysis of sol-gel processed doped and undoped TiO2 films for sensors

We have used x-ray photoelectron spectroscopy (XPS) to probe the actual surface composition of alkali-doped and undoped TiO2 films prepared by the sol-gel technique. The role of thermal pretreatments, conducted at various temperatures, and the effect of doping with Na are discussed. XPS results are compared with the electrical response of prototype devices having TiO2 films as the active element, with the help of electrochemical impedance spectroscopy (EIS) measurements.