Dye-metal oxide composite thin films for decorative applications

Organic dye-metal oxide films consisting of different metal oxide matrices and organic dye materials, respectively, with various concentration ratios were prepared by thermal evaporation. The structural, optical and mechanical properties of the composite films were studied by means of optical spectroscopy (VIS-IR, color measurements), scanning electron microscopy, atomic force microscopy and nanoindentation measurements. The films show color shifts depending on the dye concentration in the composite films and the kind of matrix material. Good film hardness, wear resistance and stability against various chemical solvents are obtained using ZrO2 matrices. Low-energy ion bombardment during deposition was performed to improve the mechanical properties of these films. The results show that the organic molecules are very sensitive to ion bombardment. The selective absorption in the visible spectral range and thus the characteristic dye color will be completely lost at ion energies greater than or equal to 80 eV and ion-to-molecule ratios >0.2, respectively.