Effect of Aluminium (Al) and Copper (Cu) Doping on Characteristics of Tin Oxide (SnO2) Thin Film

Abstract

Tin Oxide (SnO2) thin film with thickness of 300 nm is fabricated on glass substrate (2 cm × 2 cm) utilizing vacuum evaporation by fixing vacuum pressure of 2.4 × 10−6 torr and deposition rate of 0.5 Å/sec. Substrate temperature is fixed at 300°C and annealed for 15 minutes at 350°C. Aluminum (Al) and Copper (Cu) doping are performed by stacked layer method and further characterized by X-ray diffractometer (XRD) and UV-VIS-NIR spectrophotometer. XRD patterns revealed of Al and Cu doped SnO2 thin film proved it as a polycrystalline with cubic phase and variable miller indices at peak XRD intensity. Optical properties like transmittance, dielectric constant, reflectance, energy bandgap and refractive index are also calculated and found something promising. Transmittance in near-infrared region for undoped film is approximately 70% and for both Al and Cu doped films it is below 35%. Reflectance gets higher as the percentage of Al and Cu doping increase; energy bandgap falls from 3.72 eV to 3.42 eV and both refractive index and dielectric constant get higher as the percentage of Al and Cu doping enhances.