(January 8, 2016) Chemical
interconnection bridges electronic properties of graphene-nanoribbons with
zigzag-edge features.
An international research team at Tohoku University's
Advanced Institute of Materials Research (AIMR) succeeded in chemically
interconnecting chiral-edge graphene nanoribbons (GNRs) with zigzag-edge
features by molecular assembly, and demonstrated electronic connection between
GNRs. The GNRs were interconnected exclusively end to end, forming elbow
structures, identified as interconnection points (Fig. 1a).
This configuration enabled researchers to demonstrate that
the electronic architecture at the interconnection points between two GNRs
(Fig. 1b) is the same as that along single GNRs; evidence that GNR electronic
properties, such as electron and thermal conductivities, are directly extended
through the elbow structures upon chemical GNR interconnection.
This work shows that future development of high-performance,
low-power-consumption electronics based on GNRs is possible.
Graphene has long been expected to revolutionize
electronics, provided that it can be cut into atomically precise shapes that
are connected to desired electrodes. However, while current bottom-up
fabrication methods can control graphene's electronic properties, such as high
electron mobility, tailored band gaps and s pin-aligned zigzag edges, the
connection aspect of graphene structures has never been directly explored. For
example, whether electrons traveling across the interconnection points of two
GNRs would encounter higher electric resistance remains an open question. As
the answers to this type of questions are crucial towards the realization of
future high-speed, low-power-consumption electronics, we use molecular assembly
to address this issue here.
"Current molecular assemblies either produce straight
GNRs (i.e., without identifiable interconnection points), or randomly
interconnected GNRs," says Dr. Patrick Han, the project leader.
"These growth modes have too many intrinsic unknowns for determining
whether electrons travel across graphene interconnection points smoothly. The
key is to design a molecular assembly that produces GNRs that are
systematically interconnected with clearly distinguishable interconnection
points."