The combined effects of molar concentration of the precursor solution and fluorine doping on the structural and electrical properties of tin oxide films

Undoped and fluorine doped tin oxide (FTO) films have been fabricated by employing a simplified and inexpensive spray technique using perfume atomizer at comparatively lesser substrate temperature (320 °C). The combined effects of molar concentration of the precursor solution and fluorine doping on the structural and electrical properties of tin oxide films have been reported. The X-ray diffraction studies of undoped films revealed that the interstitial incorporation of Sn atoms can be controlled by employing this simple spray pattern and process conditions. The electrical studies showed that, in governing the variation in sheet resistance, the role of substitutional incorporation of F⁻ ions is predominant over the oxygen vacancies in the case of FTO films deposited from solutions having lower precursor concentration, whereas in the case of higher concentrations the role of oxygen vacancies is predominant. The quantitative results of energy dispersive X-ray analysis (EDAX) and the variations in the Fourier transform infrared (FTIR) peaks are presented as strong evidences for the above observations.