Determination of band curvatures by angle-resolved two-photon photoemission in thin films of C60 on Ag(111).
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.
Shipman
Steven T
ST
Chemistry Department, University of California-Berkeley, 94720, USA.
Garrett-Roe
Sean
S
Szymanski
Paul
P
Yang
Aram
A
Strader
Matthew L
ML
Harris
Charles B
CB