Authors : C. R. Bobade
Page Nos : 123-129
Description :
Polycrystalline Tin-doped Cadmium Oxide (Sn:CdO) thin films were deposited onto glass at low substrate temperature of 210 oC using advanced spray pyrolysis (ASP) technique. Sn doping (2-4 at%) was achieved by using stannic chloride (SnCl4.5H2O) used as a precursor. The films were grown at optimized preparative parameters. Effect of ‘Sn’ doping on the physical, electrical and optical properties of the films has been investigated. X-ray diffraction (XRD) studies show that films thus prepared are polycrystalline and have a rock salt type cubic crystal structure with preferential orientation along (111) plane. Field emission scanning electron microscopy (FESEM) micrographs show granular surface morphology and the average grain size was found to be around 152 nm. Moreover it was seen that the small grains are aggregated to form big grains/structures. In particular, the 4% Sn doped samples revealed a unique kind of triangular flower-like structured grain morphology. X-ray photoelectron spectroscopy (XPS) analysis indicated ‘Sn’ doping; while it was found from Energy Dispersive X-ray Analysis (EDAX) the extent of doping concentration and composition of the as-prepared films. A drastic increase in transmittance was seen for 4% Sn doped CdO thin films as compared to other concentrations of Sn doping in CdO thin films. Semiconducting behavior of resistivity with temperature was observed. The resistivity was found to increase with increase in ‘Sn’ doping in CdO matrix.
