Effect of Temperature on Dielectric, Impedance, and Optical Properties of Al-Doped ZnO by Wet-Chemical Process

Zinc oxide (ZnO) nanoparticles were substituted with Al in the ratio of 0 to 0.1 and synthesized using co-precipitation. Nanoparticles were characterized by X-ray diffraction and UV-visible spectroscopy. The synthesized nanoparticles of ZnO have shown a wurtzite structure. The crystallite sizes of pure and ZnO nanoparticles substituted with Al were calculated with the help of Debye–Scherrer’s equation. With the rise in Al concentration doping, there is a reduction in the nanoparticles average crystallite size. It was observed that the DC conductivity increases as temperature and Al concentration rise. The dielectric constant ε, and dielectric loss, tan δ rise with temperature rise. Complex impedance analysis distinguishes the grain and grain boundary contribution to the material. The UV-Vis spectrum has shown that as the Al doping concentration increased, Urbach energy increased, and optical conductivity was highest when 0.03 of Al was doped in ZnO (ZA03).