Study the Effect of ZnO/Cu/ZnO Multilayer Structure by Radio Frequency Magnetron Sputtering for Flexible Display Applications

Abstract

ZnO/Cu/ZnO multilayer structured glass and Polyethylene naphthalate (PEN) with different thicknesses of copper (Cu) layer were prepared by RF magnetron sputtering at room temperature. The electrical resistivity of the films was achieved at 8.6x10- 5 Ω·cm and 4.5x10-4 Ω·cm, the carrier concentration of 5.32x1021cm-3 and 1.36x1021 cm-3, low sheet resistance of 12 Ω/cm2and 16 Ω/cm2 respectively on glass and PEN substrate respectively with the optical transmission of more than 80% for both cases at the optimum copper layer thickness. The conduction mechanism of the multilayer structure has been explained in terms of metal-to-oxide carrier injection with the variation of the thickness of the Cu layer. Different optimization procedures were used to achieve good optically transparent and electrically conductive films. The structural characterizations of multilayer films were carried out by X-ray diffraction (XRD); surface morphology and topography were performed by scanning electron microscopy (SEM) and atomic force microscopy (AFM) respectively. The value of the sheet resistance of the structure was influenced by the deposition condition of both layers. The effect of the substrate and thickness of the Cu layer was investigated and illustrated.