Investigations on silver incorporated RF sputtered ZnO thin films

Abstract

In this work, ZnO thin films were fabricated using RF Magnetron Sputtering technique on ITO substrates. The operating parameters time of deposition, Argon working pressure, distance between target and substrate, oxygen pressure, RF power etc. were optimized so as to get good quality ZnO thin films. The prepared films were characterised using various techniques like XPS, SEM, EDS etc. It was observed that the sheet resistance of the pristine ZnO film was around 200 MΩcm−1 even when coated on ITO substrates. For device level application the resistance of the film must be low. Therefore silver was incorporated by sputtering, and it served the purpose of reducing the sheet resistance of pristine ZnO film. The Ag incorporated films were also characterised by the above mentioned techniques. Detailed compositional analysis was done using depth profiling method of XPS. Resistance measurements were also done in these samples. The sheet resistance decreased (from ∼ 200 MΩcm−1) to a range of about 500 MΩcm−1 by silver incorporation.