SHORT COMMUNICATION Hybrid ZnO/polymer thin films prepared by RF magnetron sputtering Edit Pál & Torben Seemann & Volker Zöllmer & Matthias Busse & Imre Dékány Received: 12 October 2008 / Revised: 17 December 2008 / Accepted: 18 December 2008 / Published online: 20 January 2009 # Springer-Verlag 2009 Abstract Zinc oxide/poly(acrylic acid) (ZnO/PAA) multi- layered hybrid films with different layer thicknesses were prepared by radio frequency magnetron sputtering. Zinc peroxide was used as precursor materials for the preparation of ZnO layers, since the zinc peroxide decomposes to ZnO during the film deposition. The films have a high transmittance in the visible region and exhibit visible photoluminescence emission. The band gap energy of the films—determined by the Tauc relationship—decreases with increasing layer thickness (3.40–3.36 eV) due to the increasing crystalline size of the ZnO particles. The morphological investigations showed that a real layered hybrid film structure formed. Keywords ZnO . Polymer . Multilayer . Magnetron sputtering . Optical properties Introduction Zinc oxide is a widely used n-type semiconductor oxide having a wide direct band gap (E g =3.37 eV) and large excitation binding energy (60 meV) [1]. Many techniques are being used to prepare undoped and/or doped ZnO thin films such as layer-by-layer (LbL) self-assembly method [2], Langmuir–Blodgett technique [3, 4], spin coating [5], chemical vapour deposition [6], spray pyrolysis [7, 8] magnetron sputtering [9–15], etc. Owing to its favourable optical, electrical and catalytic properties, thin layers of ZnO are often utilised in solar cells [16–20] as gas sensors [21, 22], as photocatalyst [2] and as antireflective coating [23]. There are only few publications where other inorganic (silicate) [2] or organic (dyes) [24] material is applied in the thin films besides the ZnO to obtain 2D hybrid structures. ZnO/clay mineral and ZnO/polymer sandwich structures were prepared by Sebők et al. [25] using LbL method. The hybrid films were used as optical sensors to detect ethanol vapour. Polymer layers such as polyimide [26], polytetrafluoro- ethylene [27], polyethylene and polypropylene [28] have also been successfully deposited by magnetron sputtering. Since currently there is no available report on the deposition of ZnO/polymer hybrid structures by radio frequency (RF) magnetron sputtering, therefore we prepared ZnO/polymer structures applying the aforementioned tech- nique. In the present work, the preparation of ZnO/ poly(acrylic acid) hybrid structures by RF magnetron sputtering technique and the effect of the layer thickness and the ageing time on the optical (transmission, reflection and photoluminescence) and on the structural properties of films are described. Colloid Polym Sci (2009) 287:481–485 DOI 10.1007/s00396-008-1992-x E. Pál : I. Dékány Department of Colloid Chemistry, University of Szeged, Aradi vt. 1., Szeged 6720, Hungary T. Seemann : V. Zöllmer : M. Busse Fraunhofer Institute IFAM Manufacturing Advanced Materials, Wiener Str. 12, 28359 Bremen, Germany I. Dékány (*) Supramolecular and Nanostructured Materials Research Group of the Hungarian Academy of Sciences, University of Szeged, Aradi vt.1, Szeged 6720, Hungary e-mail: i.dekany@chem.u-szeged.hu