Electronic structures at the interfaces between copper phthalocyanine and layered materials

Copper phtalocyanine (CuPc) films with the thickness controlled in molecular scales have been grown epitaxially on (0001) surfaces of layered materials, and electronic interaction at the interfaces have been studied by photoelectron spectroscopy. Materials with different electronic properties having different work functions (Evac) were chosen as the substrates; semiconducting MoTe2 (Evac=4.0 eV), semi-metallic highly oriented pyrolytic graphite (Evac=4.5 eV) and metallic TaSe2 (Evac=5.5 eV). Formation of interface dipole layers was found at CuPc/TaSe2 interfaces and molecular orbitals involved were identified.