Electrochemical growth and physico-chemical characterization in organic medium of Nb2O5 thin films

Investigations about the energetics and the electrical properties of niobium thin film, electrochemically grown, were performed in an organic solution of acetonitrile and lithium perchlorate. The study of the energetics of the Nb₂O₅/organic solution interface was performed by means of a non-destructive optical technique, photocurrent spectroscopy. By means of this technique, it was possible estimating the value of the flat band potential and locating conduction and valence band. A more cathodic value of flat band potential in respect with acidic solution was found in organic medium. From impedance spectra, the electrical circuit that gives best fitting values is constituted by two resistances in parallel with two constant phase elements and in series with the resistance of the electrolyte. On considering the exponential coefficient, the constant phase elements model distorted capacitances.