Effect of solvent volume on the physical properties of undoped and fluorine doped tin oxide films deposited using a low-cost spray technique

Undoped and fluorine doped tin oxide films were deposited from starting solutions having different values of solvent volume (10–50 ml) by employing a low cost and simplified spray technique using perfume atomizer. X-ray diffraction studies showed that there was a change in the preferential orientation from (2 1 1) plane to (1 1 0) plane as the volume of the solvent was increased. The sheet resistance (Rsh) of undoped SnO2 film was found to be minimum (13.58 KΩ/□) when the solvent volume was lesser (10 ml) and there was a sharp increase in Rsh for higher values of solvent volume. Interestingly, it was observed that while the Rsh increases sharply with the increase in solvent volume for undoped SnO2 films, it decreases gradually in the case of fluorine doped SnO2 films. The quantitative analysis of EDAX confirmed that the electrical resistivity of the sprayed tin oxide film was mainly governed by the number of oxygen vacancies and the interstitial incorporation of Sn atoms which in turn was governed by the impinging flux on the hot substrate. The films were found to have good optical characteristics suitable for opto-electronic devices.

► Simplified spray technique.
► Good quality undoped SnO2 films.
► Analysis on oxygen vacancies.