Chemical-vapor-deposited large-area graphene is employed as the coating of transparent substrates for the growth of the prototypical organic n-type semiconductor perfluoropentacene (PFP). The graphene coating is found to cause face-on growth of PFP in a yet unknown substrate-mediated polymorph, which is solved by combining grazing-incidence X-ray diffraction with theoretical structure modeling. In contrast to the otherwise common herringbone arrangement of PFP in single crystals and "standing" films, we report a pi-stacked arrangement of coplanar molecules in "flat-lying" films, which exhibit an exceedingly low pi-stacking distance of only 3.07 angstrom, giving rise to significant electronic band dispersion along the pi-stacking direction, as evidenced by ultraviolet photoelectron spectroscopy. Our study underlines the high potential of graphene for use as a transparent electrode in (opto-)electronic applications, where optimized vertical transport through flat-lying conjugated organic molecules is desired.
Epitaxial growth of π-stacked perfuoropentacene on graphene-coated quartz / I. Salzmann; A. Moser; M. Oehzelt; T. Breuer; X. Feng; Z. Juang; D. Nabok; R. G. Della Valle; S. Duhm; G. Heimel; A. Brillante; E. Venuti; I. Bilotti; C. Christodoulou; J. Frisch; P. Puschnig; C. Ambrosch-Draxl; G. Witte; K. Müllen; N. Koch. - In: ACS NANO. - ISSN 1936-0851. - STAMPA. - 12:(2012), pp. 10874-10883. [10.1021/nn3042607]
Epitaxial growth of π-stacked perfuoropentacene on graphene-coated quartz
DELLA VALLE, RAFFAELE GUIDO;BRILLANTE, ALDO;VENUTI, ELISABETTA;BILOTTI, IVANO;
2012
Abstract
Chemical-vapor-deposited large-area graphene is employed as the coating of transparent substrates for the growth of the prototypical organic n-type semiconductor perfluoropentacene (PFP). The graphene coating is found to cause face-on growth of PFP in a yet unknown substrate-mediated polymorph, which is solved by combining grazing-incidence X-ray diffraction with theoretical structure modeling. In contrast to the otherwise common herringbone arrangement of PFP in single crystals and "standing" films, we report a pi-stacked arrangement of coplanar molecules in "flat-lying" films, which exhibit an exceedingly low pi-stacking distance of only 3.07 angstrom, giving rise to significant electronic band dispersion along the pi-stacking direction, as evidenced by ultraviolet photoelectron spectroscopy. Our study underlines the high potential of graphene for use as a transparent electrode in (opto-)electronic applications, where optimized vertical transport through flat-lying conjugated organic molecules is desired.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
