Bandgap Modulation in Sn -Doped V₂O₅Thin Films: Role of Annealing and Dopant Concentration

In this paper, ultrasonic nebulized spray pyrolysis technique is used for formation of V2 O5 thin films on glass substrate. The thin film specimens for undoped, 1%, 2% and 7% Sn doped. A device construction based on metal-semiconductor-metal (MSM) was used to study vanadium pentoxide. Thermal evaporation and a shadow mask were used to create the MSM-based structure. These thin film samples were annealed at 400° C with uniform ramp-up and ramp-down of 5°C/min and the effect of annealing on the bandgap energy is studied experimentally by UltraViolet-Visible (UV-Vis) spectrometer and Tauc plot. A decrease in absorption coefficient value was observed with rising Sn doping concentration in annealed V2 O5 thin film. Furthermore, Tauc plot from UV-Vis spectrum showed the bandgap energy of 2.30 eV, 2.22 eV, 2.16 eV and 2.14 eV for annealed pristine, 1 %, 2 % and 7% Sn doped thin films. Our results show how Sn doping and annealing procedure can be used to tune the bandgap energy of V2 O5 based thin films. These findings suggest the application of V2 O5 thin film in optical technology and gas sensors.