Solid-state photochemistry of a Cu(II) β-diketonate complex: the photochemical formation of high quality films of copper(II) oxide

In this communication, we report the utilization of amorphous films of metal-organic molecules for the direct photochemical deposition of thin films of copper(II) oxide. This is effected by UV photolysis of amorphous thin solid films of Cu[CH3(CH2)8COCHCOC4H9]2, which results in the loss of all ligands from the coordination sphere. The acetylacetone derivative was chosen for the solid-state photochemistry because the presence of the long carbon chains or highly branched hydrocarbons substituents lowers the intermolecular interactions and allows the formation of high quality films upon spin-coating. The surface morphology of the films was observed by optical microscopy and showed excellent quality with no visible grains, islands, or other imperfections. The compositions of the films were determined by scanning electron microscopy (SEM), X-ray diffraction (XRD), and Auger spectroscopy. The copper(II) oxide films are free from carbon contamination in the bulk as shown by Auger electron spectroscopy.