Band formation in a molecular quantum well via 2D superatom orbital interactions.
By scanning tunneling microscopy and spectroscopy, we study nearly free electron band formation of the σ* lowest unoccupied molecular orbital of C6F6 on a Cu(111) surface. In fractal islands, the lowest unoccupied molecular orbital energy systematically stabilizes with the number of interacting near-neighbor C6F6 molecules. Density functional theory calculations reveal the origin of effective intermolecular orbital overlap in the previously unrecognized superatom character of the σ* orbital of C6F6 molecules. The discovery of superatom orbitals in planar molecules offers a new universal principle for effective band formation, which can be exploited in designing organic semiconductors with nearly free electron properties.
Surface Science Center and Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA.
Daniel B
DB
Dougherty
Min
M
Feng
Hrvoje
H
Petek
John T
JT
Yates
Jin
J
Zhao