Cu-doped ZnO nanoparticles: Synthesis, structural and electrical properties

Abstract

Pure and Cu doped ZnO nanopowders (5, 10, 15, 20, 25 and 30at% Cu) have been synthesized using co-precipitation method. Transmission Electron Microscopic analysis has shown the morphology of ZnO nanopowders to be quasi-spherical. Powder X-ray Diffraction studies have revealed the systematic doping of Cu into the ZnO lattice up to 10% Cu, though the peaks corresponding to CuO in 10% Cu are negligibly very small. Beyond this level, there was segregation of a secondary phase corresponding to the formation of CuO. Fourier Transform Infrared spectra have shown a broad absorption band at ∼490cm−1 for all the samples, which corresponds to the stretching vibration of Zn–O bond. DC electrical resistivity has been found to decrease with increasing Cu content. The activation energy has also been observed to decrease with copper doping i.e. from ∼0.67eV for pure ZnO to ∼0.41eV for 30at% Cu doped ZnO.