Structure, optical and electrical properties of ZnO thin films on the flexible substrate by cathodic vacuum arc technology with different arc currents

ZnO thin films were successfully deposited onto PET substrates prepared by using cathodic arc plasma deposition (CAPD) technique at a low temperature (<75 °C). Their structure, optical and electrical properties were investigated with various arc currents (40, 45, 50 and 55 A). ZnO (0 0 2) peak was clearly observed, and increased as the arc current increased from 40 A to 55 A. The calculated average crystallized sizes were around 15.9–17.7 nm. The films have an average transmittance over 85% in the visible region, and calculated values of the band gap around 3.33–3.31 eV with increase of the arc current. It was also found that a slight blue shift of optical transmission spectra was observable when decreasing the arc current. The deposited ZnO films had the lowest resistivity; about 3 × 10−3 Ω cm for the ZnO film with the arc current of 40 A.