posted on 2024-02-02, 15:38authored byMauro Marongiu, Tracy Ha, Sara Gil-Guerrero, Kavita Garg, Marcos Mandado, Manuel Melle-Franco, Ismael Diez-Perez, Aurelio Mateo-Alonso
One of the challenges
for the realization of molecular electronics
is the design of nanoscale molecular wires displaying long-range charge
transport. Graphene nanoribbons are an attractive platform for the
development of molecular wires with long-range conductance owing to
their unique electrical properties. Despite their potential, the charge
transport properties of single nanoribbons remain underexplored. Herein,
we report a synthetic approach to prepare N-doped pyrene-pyrazinoquinoxaline
molecular graphene nanoribbons terminated with diamino anchoring groups
at each end. These terminal groups allow for the formation of stable
molecular graphene nanoribbon junctions between two metal electrodes
that were investigated by scanning tunneling microscope-based break-junction
measurements. The experimental and computational results provide evidence
of long-range tunneling charge transport in these systems characterized
by a shallow conductance length dependence and electron tunneling
through >6 nm molecular backbone.