Investigation on the structural and optical properties of Zn1-xCuxO (x=0, 0.05, 0.1) sintered thick films for optoelectronic device applications

Abstract

The pure and copper doped zinc oxide Zn1-xCuxO (x=0,0.05,0.1) thick films were deposited on glass substrates by screen printing method from their nano powders, followed by sintering at 500 0 C to obtain desired stoichiometry and better adherence of films. The structural and optical properties of the samples were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM) with UV-visible spectroscopy and Raman spectroscopy. XRD patterns confirmed hexagonal wurtzite structure with minor detection of Cu and SEM micrographs revealed granular grains and porosity in films. The optical properties and the energy band gap of pure and Cu 2+ ions doped ZnO films were studied by UV-visible absorbance spectroscopy. As the doping concentration is increased, both the absorption edge and the reflectance edge is found to shift towards higher wavelengths (red shift) and the direct band gap decreased from 3.4 to 3.3 eV. The incorporation of copper in ZnO lattice is confirmed by Raman spectrum. The E2 (high) phonon and multiphoton modes are observed at 441 and 1132 cm -1 respectively in Raman spectra. *Corresponding Authors