CuI is a wide-gap, naturally p-conductive semiconductor with zincblende-type structure at ambient conditions. It unites high transparency in the visible spectral range with unsurpassed hole conductivity. Despite recent progress, several fundamental material science issues and practical problems remain before CuI can be used as multifunctional material. The Research Unit wants to close the gap between the current promising results and exploitation of the unique properties of copper iodide in real world applications employing thin films.