title: Determination of band curvatures by angle-resolved two-photon photoemission in thin films of C60 on Ag(111).
abstract: The thickness-dependent interfacial band structure was determined for thin films of C(60) on Ag(111) by angle-resolved two-photon photoemission spectroscopy. Dispersions of molecular-orbital derived bands (HOMO, LUMO+1, and LUMO+2) were acquired, and limits were placed on their possible effective masses. A group theoretic approach is also incorporated to further understand the properties of these states. The HOMO, LUMO+1, and LUMO+2 bands possess (best-fit) effective masses of -7 m(e), -7 m(e), and -12 m(e), respectively. These values are consistent with theoretical calculations, averaged over the closely spaced subbands for each state, and provide practical limits on the effective fundamental charge-transport properties of C(60) films.
authors.affiliation: Chemistry Department, University of California-Berkeley, 94720, USA.
authors.forename: Steven T
authors.initials: ST
authors.lastname: Shipman
authors.forename: Sean
authors.initials: S
authors.lastname: Garrett-Roe
authors.forename: Paul
authors.initials: P
authors.lastname: Szymanski
authors.forename: Aram
authors.initials: A
authors.lastname: Yang
authors.forename: Matthew L
authors.initials: ML
authors.lastname: Strader
authors.forename: Charles B
authors.initials: CB
authors.lastname: Harris