Journal of Modern Trends in Physics Research Online ISSN 2636-4220 DOI: 10.19138/mtpr/(14)90-99 Accepted: 2014-12-19 Shaban et al. (2014), Synthesis and characterization of Tin oxide thin film, effect of annealing on multilayer film, J. Modern Trends in Phys. R., Vol. 14 90-99 https://doi.org/10.19138/mtpr/(14)90-99 90 Synthesis and characterization of Tin oxide thin film, effect of annealing on multilayer film Mohamed Shaban 1 *, G. F. Attia 2 , Mohamed A. Basyooni 2 , Hany Hamdy 1 1 Nanophotonics and Applications (NPA) Lab, Department of Physics, Beni-Suef University, Beni-Suef 62111, Egypt 2 Space Research Lap, Solar and Space Research Department, National Research Institute of Astronomy and Geophysics (NRIAG), Helwan, Cairo, Egypt. Abstract- Nano crystalline Tin oxide thin film of multiple layers was successfully prepared by the sol-gel method with, spin coater has been used to deposit the films. The starting material is SnCl2. The SnO2 material was characterized by X-ray Diffraction (XRD), Scanning Electron Microscope (SEM). The optical properties (A, T, R) of the SnO2 thin film of various annealing temperatures (400,500,600 Co) have been studied. Characterization results indicated that the products are composed of crystalline SnO2 nanoparticles which exhibit the cassiterite-type tetragonal crystal structure. SEM revealed that with increase annealing temperature, the uniformity of the film increased. XRD measurements showed that the grain size increased from 1.06, 1.48, 1.71 nm. The variations of the refractive index (n), extinction coefficient (K) and Optical Conductivity with the wavelength have been studied. Nevertheless, the variation of the optical band gap with film thicknesses shows a significantly decrease in the values of the band gap with increase the film thicknesses. * Correspondence Author – Tel.: +20-111-212-4309; +20-127-449-3440; Fax: +2-082-233-4551; Email: mssfadel@yahoo.com. Keywords- SnO2 thin film, XRD, Spin coater, annealing temperatures, Sol-gel. 1. INTRODUCTION SnO2 film is a wide band gap (3.6ev) n-type semiconductor with a highly resistant to moisture and acids [1], gas sensing materials for gas sensor devices [2], aerospace vehicles [3]. The methods that have been employed to prepare SnO2 thin films include photochemical deposition [4], RF sputtering [5], sol –gel process [6, 7] chemical vapor deposition [8, 9], physical vapor deposition [10], spin-coating [11] and spray pyrolysis [12]. Sol-gel technology has emerged as an ideal fabrication method due to its low processing cost and its ability to control the morphology of the film. It has been reported that SnO2 films prepared by spin-coating method can be used as gas sensors [13–15] and solar cell system electrode materials. 2. EXPERIMENTAL DETAILS SnCl2.2H2O was used as precursor material. 8.374 gm of SnCl 2.2H2O was dissolved in 100 ml of absolute ethanol. The mixture was refluxed and stirred at 353 K for 3 hours and then it was allowed to cool to the room temperature for 1 hour with continuous stirring. We used a glass substrate to deposit the solution with the help of the commercial spin coater Figure (1). For film deposition, the glass substrates were cleaned for 30 minutes in H2SO4 : H2O2 : 3 : 1, then for 10 minutes in acetone with boiling temperature, also for 10 minutes in methanol with boiling, then rinsed in de- ionized water and dried in 150C. We kept the spin coater speed at 2100 rpm for 30 seconds. We started from one layer until twelve ones and under those conditions, we found that the twelfths one was the fitted one. With twelve multi layers, the coated glass slide was air annealed at 400, 500 and 600 for 10 minutes. The slide was then allowed to cool to the room temperature.