Improving the performance of fluorine-doped tin oxide by adding salt

•A method to improve FTO performance using the addition of salt•The FTO film exhibited high performance of conductivity and light transmittance.•This technique is low-cost, fast and scales-up easily using simple devices.

High-performance fluorine-doped tin oxide (FTO) films were fabricated via a spray deposition technique with salt added to the precursor. The addition of NaCl in the precursor improved the conductivity of the FTO films. Increasing the NaCl concentration to its optimal concentration reduced the sheet resistance of the FTO film. The optimal values for the addition of a NaCl were 0.5, 0.5, 1.5, and 1.5 at.% for the FTO film prepared using NH4F concentration of 4, 10, 16, and 22 at.%, respectively. The lowest sheet resistance of the salt-added FTO film was 4.8 Ω/□. The FTO film averaged a transmittance of more than 80% in the visible range region (λ = 400–800 nm). XRD diffractograms confirmed that the crystal structure of the as-grown FTO film was that of a tetragonal SnO2 and that the addition of salt improved its crystallinity. This film has the potential for use as an electrode for dye-sensitized solar cells (DSSCs).