Crystal Structure of Epitaxial Quaterthiophene Thin Films Grown on Potassium Acid Phthalate

Synchrotron X-ray diffraction at grazing incidence has led to the identification of a new crystal structure of quaterthiophene (4T, see Figure). Epitaxial growth of the oligothiophene, deposited by organic molecular beam deposition (OMBD), on a potassium acid phthalate (KAP) crystal substrate is demonstrated on the basis of the commensurability of the 4T crystal (ac diagonal) with the b-axis of the KAP crystal.