No abstract

Al-doped Tin Oxide (SnO 2) nanostructured (ATO) thin films are prepared by Spray Pyrolysis technique on glass substrates Prepared at 400˚C and annealed at 500°C, 600°C. Using a solution consisting of SnCl 4 .5H 2 O starting material and doping source was AlCl 3 with various Al doping ratio. Sn 1-x Al x O 2 (x = 0.04, 0.06 and 0.08) were dissolved in ethanol and stirred four hours at 50˚C. The effect of changes in doping content and annealing effect of Al:SnO 2 nanostructured thin films was investigated. The result of X-ray diffraction has shown that peak located at around 2Ѳ = 37.9° is corresponding to (200) plane which confirmed the presence of SnO 2 in tetragonal crystal system. All the observed characteristic peaks are well matched with the standard data base values. The UV-Visible transmittance figures are clearly depicting that all the prepared thin films are having transparency of 80%, the optical band gap was estimated to be around 2.56ev to 3.6ev. The scanning electron microscopic (FESEM) analyses show the crack-free and dense nature of the thin film formation. The size of the particle was measured from FESEM images and it was found to be in the range of 40-54nm. In AFM the average crystallite size was estimated 45nm and the root mean square roughness value was found to be 20 nm. EDAX to confirm the presence of dopant elements in the nanostructured thin films.

In recent years, a transparent conducting oxide (TCO) SnO2 semiconductor have gained considerable attention due to their potential application in gas sensors. More number of studies on TCO oxide have focused on the semiconducting metal oxides in which an intensive argument is that the transparent semiconductors. The SnO2 thin films were deposited at 400 °C and then annealed at 500 °C and 600 °C and its structural, optical and electrical properties were characterized. The doping stoichiometric ratio was maintained as 4% and the resulting solution was sprayed on glass substrate which was kept at nozzle distance of 25 cm and the spray rate was 10 mL/min. The prepared pure SnO2 thin films have been characterized by different methods such as XRD, FESEM, UV-Vis NIR and EDAX analyses. It was found that the nanocrystalline SnO2 grains possesses structural features of the tetragonal rutile structure. Hence the prepared thin films are justified to be nanocrystalline and also the mean crystalline size decreased with respect to annealing temperature.