Surface free energy and wettability properties of transparent conducting oxide-based films with Ag interlayer

[Display omitted] •TCO, TCO/TCO, TCO/Ag and TCO/Ag/TCO films were prepared by magnetron sputtering.•SFE, wettability and Wa were studied by various surface thermodynamics approaches.•Theoretical SFE and Wa results are discussed in combination with XRD, AFM and SEM.•The presence of Ag interlayer decreases the SFE of TCO-based films considerably.•Work of adhesion between AZO and Ag is stronger than the other TCO/Ag interfaces. ITO, ZTO, AZO and Ag are commonly used in transparent conducting oxide (TCO)/metal/TCO electrodes to form multilayered thin films on a suitable substrate. A detailed surface free energy (SFE) knowledge of these films is critical to design desirable TCO-based sandwich structures. In this study, TCO/Ag/TCO multilayer thin films were coated onto glass substrates using ITO, ZTO, AZO and Ag targets by magnetron sputtering. The wettability properties of TCO, Ag interlayer and TCO/Ag/TCO were evaluated by contact angle measurements of seven different liquids having various surface tension values. The dispersive and polar components of SFE were calculated using geometric and harmonic mean approaches. The acidic and basic components of SFE were calculated using van Oss-Chaudhury-Good method. Following this, the work of adhesion values between TCO films and Ag interlayer were estimated using SFE values of the films. The results show that the SFE components of the surfaces differ depending on the TCO type, the total SFE values of TCO/Ag/TCO films were lower than that of TCO films, and AZO/Ag adhesion is stronger than the other TCO/Ag structures. The reasons behind these differences were discussed by evaluating the SFE, XRD, AFM and SEM analysis simultaneously.