NanoVidere - Research on Coating Deposition

• Applicant: Professor Dr. Wolfgang Maus-Friedrichs
• Subject Area: Synthesis and Properties of Functional Materials ; Physical Chemistry of Solids and Surfaces, Material Characterisation
• Term: from 2019 to 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 413604212

In this project, we will develop, optimise and analyse photochromic coating systems. These coatings shall render possible various applications of the nanoscopy with resolutions beyond today’s state of the art for microscopy and spectroscopy. In order to achieve this goal, we will closely collaborate with the Institute of Organic Chemistry and the Institute of Physical Chemistry, who participate in this proposal package with their own project proposals.Photochromic coating are already described in the literature related to lithographic processes, where they are call adsorbance-modulaytion layers (AML). The high resolution and image quality envisioned for the new nanoscopic techniques require rather thin and efficient AML, with the projected thickness of 100 nm being thinner than the best state-of-the-art coating published in the literature by a factor of 4. Further, the AML requires a suitable viscosity, thermal conductivity and photochromic stability. Since multiple measurements will be taken within a diffraction-limited area in order to achieve images at highest resolutions, secondary effects such as optically induced rotation of photochromic molecules, so-called "hole burning", need to be prevented. All such effects are dependent mainly on the environment around the photochromic molecules, and shall be minimized by developing a suitable cross-linked, amorphous matrix.The photochromic molecules will be applied to the surface within a liquid phase, in order to be protected within this liquid film. Subsequently, the films will be polymerised using a non-thermal plasma. This approach has already been described and demonstrated in the literature, and shall be extended to deliver the desired AML functionalities. The typical properties of these special plasma polymers shall be exploited and optimized for their elasticity, tensile properties or inner viscosity. Thereby, the coatings will allow for the changes in geometrical shape, which the molecules undergo upon photochromic switching. These processes shall also include specifically tailored cross-linking reactions. Further, a gradient of physical and chemical properties will be induced such, that the surface exhibits a suitable anti-reflex behaviour for contactless measurements or a suitable surface hardness and stability for measurements using immersion objectives.

• DFG Programme: Research Grants