Abstract
Zinc oxide (ZnO) films were deposited on flexible polyethylene terephthalate (PET) substrates by direct current (DC) magnetron sputtering in ArO2 environment. Singly charged copper ions (Cu+1) of doses 1 × 1011, 1 × 1012, 1 × 1013, and 1 × 1014 ions/cm2 were implanted in ZnO films using Pelletron Accelerator at room temperature. X-ray diffraction revealed c-axis oriented ZnO film having hexagonal wurtzite structure. The crystallite size of ZnO film was decreased with increasing Cu+1 dose up to 1 × 1012 ions/cm2, and then it started increasing with further increase of ion dose. The decrease in crystallite size was attributed to ion-induced lattice disorder in the film whereas the increase in crystallite size at higher doses (>1 × 1012 ions/cm2) was associated with the thermally induced annihilation of defects. The lattice parameter of ZnO was decreased after Cu+1 implantation at different doses that was ascribed to the lower ionic radius of Cu+1 as compared to the Zn+2. The UV–Vis spectroscopic analysis revealed a decrease in band gap of ZnO film after Cu+1 implantation up to 1 × 1013 ions/cm2. However, by increasing ions dose to 1 × 1014 ions/cm2, the band gap was increased. The electrical resistivity of ZnO film was increased at 1 × 1011 ions/cm2 and then decreased with further increase of the dose value.
•C-axis oriented ZnO film was deposited on PET by DC magnetron sputtering.•Cu+1 implantation in ZnO film was carried out at different doses.•Ion implantation decreases film crystallinity and its lattice parameter.•The changes in band gap and electrical resistivity are inconsistent with ion dose.