Linear Chains of Styrene and Methyl-Styrene Molecules and their Heterojunctions on Silicon: Theory and Experiment

Abstract

We report on the synthesis, STM imaging and theoretical studies of the structure, electronic structure and transport properties of linear chains of styrene and methyl-styrene molecules and their heterojunctions on hydrogen-terminated dimerized silicon (001) surfaces. The theory presented here accounts for the essential features of the experimental STM data including the nature of the corrugation observed along the molecular chains and the pronounced changes in the contrast between the styrene and methyl-styrene parts of the molecular chains that are observed as the applied bias is varied. The observed evolution with applied bias of the STM profiles near the ends of the molecular chains is also explained. Calculations are also presented of electron transport along styrene linear chains adsorbed on the silicon surface at energies in the vicinity of the molecular HOMO and LUMO levels. For short styrene chains this lateral transport is found to be due primarily to direct electron transmission from molecule to molecule rather than through the silicon substrate, especially in the molecular LUMO band. Differences between the calculated position-dependences of the STM current around a junction of styrene and methyl-styrene molecular chains under positive and negative tip bias are related to the nature of lateral electron transmission along the molecular chains and to the formation in the LUMO band of an electronic state localized around the heterojunction.

17 pages plus 11 figures. To appear in Physical Review B

References in corpus (14)

• ab initio modeling of open systems: charge transfer, electron conduction, and molecular switching of a C_{60} device
• Theoretical Study of Electrical Conduction Through a Molecule Connected to Metallic Nanocontacts
• Electrical transport through single-molecule junctions: from molecular orbitals to conduction channels
• Electron Transport Through Molecules: Self-consistent and Non-self-consistent Approaches
• Silicon-based molecular electronics
• The Smallest Molecular Switch
• Molecular Spintronics: Spin-Dependent Electron Transport in Molecular Wires
• Fullerene-based molecular nanobridges: A first-principles study
• End group effect on electrical transport through individual molecules: A microscopic study
• Orientational dependence of current through molecular films
• State Orthogonalization by Building a Hilbert Space: A New Approach to Electronic Quantum Transport in Molecular Wires
• Intermolecular Effect in Molecular Electronics
• Antiresonances in Molecular Wires
• Local-field effects in current transport through molecular electronic devices: Current density profiles and local non-equilibrium electron distributions

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