2015/02/10 by Vinícius C. Zoldan, Ricardo Faccio, André A. Pasa · 1 citation
Engineering · Physics and Astronomy · #Molecular Junctions and Nanostructures #Force Microscopy Techniques and Applications #Photonic and Optical Devices
paper · pdf · doi:10.1038/srep08350
openalex publication_date 2015/02/10 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/23
Looking for single molecule electronic devices, we have investigated the charge transport properties of individual tetra-phenylporphyrin molecules on different substrates by ultrahigh-vacuum scanning tunneling microscopy and spectroscopy and by first-principles calculations. The tetra-phenylporphyrins with a Co atom (Co-TPP) or 2 hydrogens (H2-TPP) in the central macrocycle when deposited on Cu3Au(100) substrates showed a diode-like behavior with p and n type character, respectively. After removing the central hydrogens of H2-TPP molecule with the STM tip an ohmic behavior was measured. The rectifying effect was understood from the theoretical point of view by assuming for Co-TPP HOMO conduction and for H2-TPP LUMO conduction, both selectively elected by the hybridization of states between molecule and substrate surface.