Investigating the Effect of Annealing Temperatures on SnO2 Nano Structural Thin Films and their Properties

Md. Tareq Rahman; Z. Ahmed; Y. Ahmed; M. S. Rahman; F. T. Z. Toma

Abstract

As deposited and two different annealing temperatures (500°C and 600°C) of Tin dioxide (SnO2) thin films are prepared on glass substrates by Chemical Bath Deposition (CBD) technique and subsequently their structural, morphological, optical and electrical properties are investigated and analyzed as a function of annealing temperature. It’s found that SnO2 films exhibit different nanostructures at different annealing temperatures. XRD analysis confirms that both deposited and annealed films are cubic structure in nature. The crystalline size as well as the crystalline quality of the film are found to increase with the increase of annealing temperature to a certain point. Crystallite size from structural analysis are 25.47 nm, 27.57 nm, 34.05 nm and the grain size from morphological analysis are 60 nm, 85 nm 100 nm respectively. The result shows that with an increase in annealing temperature, the value of crystallite size and particle size are also increases so that there is a good agreement between XRD and SEM measurements. From UV-visible spectroscopy it is shown that transmittance of the SnO2 thin film decreasing with increasing the annealing temperature. As the annealing temperature increases band gap value decreases as 3.86 eV, 3.84 eV and 3.83 eV respectively. It is also confirmed that the conductivity is increasing with increasing the annealing temperature from electrical analysis. In this research work the CBD process is able to synthesize high quality crystallite thin films and the annealing temperature influences all the properties of the surface morphology, structural, optical and electrical properties of SnO2 thin films.

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