Optical properties of Zinc doped tin oxide synthesized by mechanochemical processing

Simple doping process of Zinc (Zn) with Tin oxide (SnO₂) was successfully prepared by the mechanochemical process, followed by a heat treatment and leaching. The raw materials are Tin Chloride (SnCl₂) as a base element, Sodium Carbonate (Na₂CO₃) as an oxidizer and Sodium chloride (NaCl) as a diluent, while Zinc Chloride (ZnCl₂) as a doping element. In this paper, we with fix wavelength investigated the effect of different concentration of Zn dopant on the optical properties of SnO₂. The chemical formula of doped SnO₂ will be Sn_1-xZn_xO₂. The peaks of the X-ray Diffraction (XRD) prove that all Zn had been successfully doped into SnO₂ host. The average sizes of crystalline were around 25 to 44 mm and it was calculated by using Scherrer´s equation. While Ultraviolet-visible spectroscopy (UV-VIS) and photoluminescence were used to analyze the energy gap differences of pure SnO₂ and doped SnO₂ with varying Zn concentration. Results show that increasing in the concentration can decrease the volume of samples. Red shift in energy gap (E_g) with an increasing Zn concentration (x ≤ 0.06) could be attributed to the Burstein-Moss effect that relates the E_g with the crystallite size of SnO₂ formed before and after the doping process. The blue shift in E_g at x>;0.06 was possibly due to excess oxygen and may also be affected by sudden increases in crystallite size. The emission intensity was changed inversely with the E_g.