Synthesis and Characterization of Ni-doped ZnO Thin Films for Diluted Magnetic Semiconductor by Spin Coating Technique

Abstract

Ni-doped ZnO thin films were synthesized by spin coating method on glass substrate with Ni concentration 0 to 5%. Films were fabricated in two different ways to study the effect of electrical, optical and magnetic properties of Ni doped ZnO thin films. Those two solutions were prepared by dissolving zinc acetate dehydrate, nickel (II) nitrate, diethanolamine (DEA), NaOH, methanol and ethanol. Thin films were fabricated by post-heating and pre-heating at 300°C for 10 minutes and finally annealed at different temperature maximum up to 500°C for 1 h respectively. The influence of the electrical, optical and magnetic properties of Ni doped ZnO thin films were investigated using FTIR, thickness profilometer, UV-Vis spectrophotometer, four probe technique and vibrating sample magnetometer (VSM). The result of FTIR shows the stretching vibration of the ZnO bond and Ni doped ZnO nanoparticles. The conductivity of ZnO is increased and hence electrical properties are improved. The electrical conductivity was increased with the concentration of Ni then decreased. Optical analysis was done on all thin films and pre-heating process shows the maximum optical transmittance and minimum absorbance that indicates the significant change of optical band gap. The vibrating sample magnetometer measurement results show no magnetic hysteresis loop. Ni doped ZnO thin film was successfully synthesized by spin coating method, characterization result suggest that the samples are semiconductor but does not show ferromagnetic behavior.