Tracing the Incorporated Fluorine in Spray Deposited Nanocrystalline Tin Oxide Thin Film

Pure and fluorine incorporated tin oxide thin films are synthesized using a cost – effective spray pyrolysis technique. The dependence of the morphology, structure, optical properties, and sheet resistance of the prepared SnO2: F films, on the concentration of fluorine in spray solution are reported. The 2D & 3D AFM images show observable changes in grain size and shape. The XRD patterns are considered as a good monitor for fluorine in SnO2 lattice. The crystallite size is found to be in the range 18 to 40 nm as calculated from XRD patterns. The energy gap of the pure sample is larger than that reported for samples having larger crystallite size, in micron and submicron ranges. The plasma frequencies ωp of the F incorporated samples exhibit blue shift due to increase in carrier concentration. The electron concentration, mobility, mean free path and Fermi energy are calculated from the experimentally determined p. Sheet resistance is measured and correlated with the reflectance at  = 2500 nm. The figure of merit and performance coefficient are estimated. It is found that prepared SnO2: F could be considered as a promising candidate for solar energy applications and optoelectronic devices.