title: Imaging molecular orbitals by scanning tunneling microscopy on a passivated semiconductor.
abstract: Decoupling the electronic properties of a molecule from a substrate is of crucial importance for the development of single-molecule electronics. This is achieved here by adsorbing pentacene molecules at low temperature on a hydrogenated Si(100) surface (12 K). The low temperature (5 K) scanning tunneling microscope (STM) topography of the single pentacene molecule at the energy of the highest occupied molecular orbital (HOMO) tunnel resonance clearly resembles the native HOMO of the free molecule. The negligible electronic coupling between the molecule and the substrate is confirmed by theoretical STM topography and diffusion barrier energy calculations.
authors.affiliation: Laboratoire de Photophysique Moleculaire, CNRS, Bat. 210, Universite Paris Sud, 91405 Orsay, France, and CEMES-CNRS, 29 rue J. Marvig, P.O. Box 4347, F-31055 Toulouse Cedex, France. amandine.bellec@u-psud.fr
authors.forename: Amandine
authors.initials: A
authors.lastname: Bellec
authors.forename: Francisco
authors.initials: F
authors.lastname: Ample
authors.forename: Damien
authors.initials: D
authors.lastname: Riedel
authors.forename: Gérald
authors.initials: G
authors.lastname: Dujardin
authors.forename: Christian
authors.initials: C
authors.lastname: Joachim
mesh_terms: D004563:Electrochemistry / Q000379:methods*; D007089:Image Enhancement / Q000379:methods*; D008422:Materials Testing / Q000379:methods; D016252:Microscopy, Scanning Tunneling / Q000379:methods*; D015336:Molecular Probe Techniques; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D036103:Nanotechnology / Q000379:methods*; D010316:Particle Size; D012666:Semiconductors