Highly ordered phthalocyanine thin films on a technically relevant polymer substrate.

We have studied the molecular orientation of well-known representatives of organic semiconductors from the family of the phthalocyanines [copper phthalocyanine (CuPc) and its perfluorinated relative sCuPcF₁₆)] on a conducting polymer thin film using polarization-dependent x-ray absorption spectroscopy. As a polymer substrate PEDOT:PSS [a mixture of poly-3,4-ethylenedioxy-thiophene (PEDOT) and polystyrenesulfonate (PSS), which is often applied as an electrode material in (all-)organic semiconductor devices] was spin coated onto indium-tin-oxide substrates. Even if the interfaces themselves are relatively ill defined (we found recently a mixing of the two organic materials and charge-transfer processes), a very high degree of molecular ordering is observed in the 20—50 nm thick phthalocyanine films. [ABSTRACT FROM AUTHOR]