Structural and Electrical Studies of NixSn1-xO2 Sn Dopped Nickel Oxide Thin Film by Jet Nebulizer Spray Pyrolysis Technique for Photodiode and Solar Cell Applications

Abstract

The dissertation deals with preparation and characterization of NixSn1-xO2 thin films by the jet nebulizer spray pyrolysis technique at optimized temperature 450°C with Ni dopants. The films were analysed to understand the structural, surface morphology, optical and electrical studies for NixSn1-xO2 thin. Moreover, in the case of transparent oxide films, the thickness increases linearly with time of spray. Also, the growth of thin films is temperature dependent. At low temperatures, the growth rate is controlled by activated processes, such as adsorption, surface diffusion chemical reaction and desorption. However, at high temperatures, the activated processes occur so fast and the molecules do not dam up on the substrate. Growth rate also depends on the size of the droplets, because the decomposition of droplet is temperature dependent. If the droplet size is large, the heat absorbed from the surroundings will not be sufficient to vaporize entirely the solvent on the way to the substrate and adversely affect the kinetics of the reaction. The XRD Pattern of NixSn1-xO2 shows the polycrystalline nature with orthorhombic structure and is oriented through (021) direction. The grain size of the prepared films is increased up to x=0.2 and then decreased slightly, for x= 0.8 the grain increases.  The conductivity of NixSn1-xO2(x=0) at room temperature is 2.8×10-4s/cm and the other compositions (x=0.2, 0.4, 0.8) show the decrease of conductivity to 2.4×10-6s/cm. The maximum transmittance ( 75%) shows in IR region and 70%of transmittance in the visible region at x=0.4. The band gap value of NixSn1-xO2 films is 2.96, 2.98 and 3.0 ev for x=0.8 0.2 and 0.4 respectively. It can be used for diode and solar cell applications due to the higher transmittance and decreases of band gap energy.