Effect of Carrier Gas on Spray Pyrolysis Deposited SnO₂ Thin Films

Abstract

Nanostructured SnO2 thin films are synthesized by the chemical Spray pyrolysis method in presence of air and nitrogen as carrier gas. The study has emphasized on the impact of carrier gas on the underlying, electrical, and optical properties of the deposited thin films. XRD studies uncover that there is no variation in the crystalline structure of the film. The SnO2 thin films prepared using nitrogen as carrier gas is found more conductive as compared to the film prepared using air as a carrier gas. The change in conductivity is due to the increased oxygen deficiency in the nitrogen atmosphere. The HBM and EMA models are used to calculate particle radius by optical absorption data, showing the particle diameter is low for nitrogen as compared to air as carrier gas. The activation energy is also found to decrease in presence of nitrogen as carrier gas. This may be due to shallow donor and deep acceptor levels of semiconductors. The decrease in particle size increases the number of surface atoms, responsible for a decrease in activation energy of films.