November

Picture of the Month - November 2021

Electrochromic tungsten oxide films for Smart Windows

Chromogenic thin films are critical building blocks for Smart Windows, allowing the flow of visible light and thermal radiation to be modulated in buildings for an improved climate control. Electrochromic materials such as tungsten oxide are well established in those devices. By intercalation of suitable ions and the resulting electrochemical reduction, the material can be switched from a colorless transparent to a deep blue optical state. Tungsten oxide thin films were grown by ion-beam sputter-deposition, a variant of sputter deposition, which allows a more precise control of the sample temperature. Suitable coating properties for the electrochromic application can be achieved by specific selection of the gas composition used in the process. Here, morphological as well as compositional properties, among others, play a crucial role and can be studied by scanning electron microscope (SEM) or X-ray photoelectron spectroscopy (XPS).

Publication: Mario Gies, Fabian Michel, Christian Lupó, Derck Schlettwein, Martin Becker, Angelika Polity „Electrochromic switching of tungsten oxide films grown by reactive ion-beam sputter deposition“
J Mater Sci 56, 615–628 (2021), https://doi.org/10.1007/s10853-020-05321-y.

This picture was submitted by Mario Gies, group of Dr. Angelika Polity.

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