Direct observation of an organic superlattice structure.

Organic multilayered thin films of copper phthalocyanine (CuPc) and naphthalene-1,4,5,8-tetracarboxylic-1,8:4,5-dianhydride were cabricated by an organic molecular beam deposition technique. The analyses by an x-ray photoelectron spectroscopy and a transmission electron microscopy directly revealed an alternating layer-by-layer structure, with a few nanometers thickness for each layer. The optical absorption spectra at the Q band for CuPc layers indicates an extraordinary electronic state in an organic superlattice structure