The Influence of Annealing Temperature on Optical Properties of Tin Oxide (SnO2) Thin Films Prepared by Thermal Evaporation Process

The research paper reveals study of influence of annealing temperature on optical properties of Tin Oxide (SnO2) thin films prepared by Thermal Evaporation process. Tin Oxide thin films were synthesized on glass substrate (corning 7059) by Thermal Evaporation unit (model 12A 4D) and annealed at different temperatures (100oc, 200oc, 300oc & 400oc) for different durations (1hr, 2hr, 3hr). Optical characteristics were analyzed from the transmission spectrum data which was obtained from UV/VIS spectrophotometer (model ELICO-159). From the study of optical properties it was observed that all the samples exhibited maximum transmittance above 70 %, average transmittance was maximum at 100oc for each annealing time. Refractive index of the films was varied with respect to annealing time & temperature, it was maximum 2.26 at 200oc annealed for 1 hr and minimum with value 1.93 at 100oc for 3hr annealing. The energy gap was calculated as maximum at 300oc temperature for all annealing durations. The optical absorption coefficient a was found in the order of 104cm-1 to 105cm-1.