Structural and Optical Properties of Ni:ZnO Thin Films-Effect of Annealing and Doping Concentration

Abstract

Zn1 xNixO thin films were prepared on glass substrate by sol-gel dip coating method. The concentration of Ni in the films varies as x=0.02,0.04,0.06,0.08 and 0.10.To understand about the influence of annealing temperature on the structural and optical properties, the Zn0:94Ni0:06O thin films are annealed at three different temperatures. The XRD analysis indicates that the prepared films are still in the ZnO hexagonal wurtzite structure- suggests that Ni 2+ ions are successfully substituted into ZnO host lattice without altering the structure. The optical band gap energy shows a decreasing tendency, irrespective of the doping concentration and annealing temperature owing to p-d exchange interaction and improved crystallinity. The PL spectra of the films shows peaks at UV, Violet and Blue regions due to the presence of intrinsic defects in the band gap.