Structure of thin films of poly(3,4-ethylenedioxythiophene)

Thin films (50-400 nm) of tosylate-doped poly(3,4-ethylenedioxythioph ene) (PEDOT) on various substrates have been studied by grazing incid ence diffraction, using synchrotron radiation. The material was found to be highly anisotropic. This is correlated with a strong anisotrop y observed in its optical and electronic properties. The crystalline order is of a paracrystalline kind. A structural model is presented, which corroborates with the optical anisotropy.