Copper iodide synthesized by iodization of Cu-films and deposited using MOCVD

We report the thin film deposition of copper iodide with zincblende type structure (γ-CuI) via metal-organic chemical vapor deposition (MOCVD). Single crystals and thin films of Cu and γ-CuI could be formed on various substrates from cyclopentadienylcopper triethylphosphine (CpCuPEt3) and ethyliodide (C2H5I) as precursors for copper and iodine, respectively. Additionally, the chemical reaction behavior of thermally evaporated and MOCVD deposited elemental copper films with C2H5I is examined. SiO2 glass and various single crystalline oxides and semiconductors were used as substrates. For all cases X-ray diffraction measurements revealed polycrystalline γ-CuI with zincblende type structure; other CuI phases could not be detected. Photoluminescence measurements show a broadened peak at 420 nm due to donor-acceptor pair recombination. Intense peaks at shorter wavelengths are attributed to excitonic emissions.