Comparative analysis of structural and photoelectrochemical properties of pure and Sb doped SnO_2 functional electrode

摘要

The purpose of this work was to analyze the electrochemical properties (C-E) and (I-E) of SnO2 thin films grown onto glass substrates by atmospheric pressure chemical vapor deposition (APCVD) and to correlate them with the microstructure i.e. texture and crystallography. The microstructure is one of the authentic monitor and the "memory" of materials processing that influences strongly the physical properties. The polycrystalline films present a good crystallinity; all peaks are assigned to the rutile phase and the films texture shows a dependence on the preparation conditions. The films deposited by APCVD under different conditions and Sb doping have been characterized by the Mott-Schottky plots and electrochemical impedance spectroscopy (EIS) both in the dark and under illumination. The photoelectrochemical results show the effectiveness of SnO2 films toward the chromate reduction. The structures like Sb doped SnO2-glass/chromate solution provide variable electrochemical properties as well as different absorbance under solar light which confirm the reduction of HCrO4- to trivalent state. We also show, through the EIS graphical representation of SnO2-Sb films-glass/chromate solution that the values of the electrical components relaxation system, conductivity and dielectric constants, are correlated with both the growth conditions and doping level.