Annealing Effect on Structural and Optical Properties of SnO2 Thin Films

Abstract

Abstract Thin solid films of SnO2 were deposited by chemical vapor deposition (CVD) method on glass substrate at 450C and 2.5L/min.air flow rate. Deposited films were annealed at different temperature (200,300,400,500) C in air for 60 minutes. Structural properties have been studied for annealed and unannealed films. It was found that the films have polycrystalline structure with grain diameter(190-230)A depend on annealing temperature. And the crystal structure is tetragonal with lattice constants (a=b=4.782 ,c=3.233)A°. Optical properties also studied for annealed and unannealed films using UV-visible spectroscopy. The transmission spectra showed higher transparency over the visible wave length region with maximum value (85-95)% depend on annealing temperature. Absorption edge energy is increased by annealing temperature from (3.93 to 4.1)eV while Optical energy gap is not affected by annealing and it is found to be (4.17)eV.