6 research outputs found
Molecule-Electrode Interface Energetics in Molecular Junction: a Transition Voltage Spectroscopy Study
We assess the performances of the transition voltage spectroscopy (TVS)
method to determine the energies of the molecular orbitals involved in the
electronic transport though molecular junctions. A large number of various
molecular junctions made with alkyl chains but with different chemical
structure of the electrode-molecule interfaces are studied. In the case of
molecular junctions with clean, unoxidized electrode-molecule interfaces, i.e.
alkylthiols and alkenes directly grafted on Au and hydrogenated Si,
respectively, we measure transition voltages in the range 0.9 - 1.4 V. We
conclude that the TVS method allows estimating the onset of the tail of the
LUMO density of states, at energy located 1.0 - 1.2 eV above the electrode
Fermi energy. For oxidized interfaces (e.g. the same monolayer measured with Hg
or eGaIn drops, or monolayers formed on a slightly oxidized silicon substrate),
lower transition voltages (0.1 - 0.6 V) are systematically measured. These
values are explained by the presence of oxide-related density of states at
energies lower than the HOMO-LUMO of the molecules. As such, the TVS method is
a useful technique to assess the quality of the molecule-electrode interfaces
in molecular junctions.Comment: Accepted for publication in J. Phys. Chem C. One pdf file including
manuscript, figures and supporting informatio
Paul RicĆur, die narrative IdentitĂ€t
Traduction de P. RicĆur, "L'identitĂ© narrative", Esprit, 7-8, juillet-aoĂ»t 1988.info:eu-repo/semantics/publishe
Molecule/Electrode Interface Energetics in Molecular Junction: A âTransition Voltage Spectroscopyâ Study
We assess the performances of the transition voltage
spectroscopy
(TVS) method to determine the energies of the molecular orbitals involved
in the electronic transport through molecular junctions. A large number
of various molecular junctions made with alkyl chains but with different
chemical structure of the electrode/molecule interfaces are studied.
In the case of molecular junctions with âclean, unoxidizedâ
electrode/molecule interfaces, that is, alkylthiols and alkenes directly
grafted on Au and hydrogenated Si, respectively, we measure transition
voltages in the range 0.9â1.4 V. We conclude that the TVS method
allows estimating the onset of the tail of the LUMO density of states,
at energy located 1.0â1.2 eV above the electrode Fermi energy.
For âoxidizedâ interfaces (e.g., the same monolayer
measured with Hg or eGaIn drops, or monolayers formed on a slightly
oxidized silicon substrate), lower transition voltages (0.1â0.6
V) are systematically measured. These values are explained by the
presence of oxide-related density of states at energies lower than
the HOMO/LUMO of the molecules. As such, the TVS method is a useful
technique to assess the quality of the molecule/electrode interfaces
in molecular junctions