Environmental Engineering Reference
In-Depth Information
achieved and the contact resistances between the devices and
electrodes are very low. More importantly, the plane-patterned
graphene-based electronics can benefit from the advantages of the
existingplanar technologies.
In ever-smaller integrated circuits, the heat dissipation becomes
more and more serious due to the increased heat generation
per unit area and the reduced thermal conduction caused by
increasingly strong boundary and interface scattering. Therefore,
thermal management has become a critical issue for future
developmentof(graphene-based)nanoelectronics.Atpresent,most
researchfocusesontheelectronictransportpropertiesofgraphene-
based nanodevices. In contrast, much less is known about their
thermal-transport properties, though such kind of knowledge and
understanding is urgently needed for practical applications. We
investigatethermal-transportpropertiesofgraphene-baseddevices
by the NEGF method. More details of this study can be found in
Ref. [51].
We focus on two types of nanodevices: graphene junctions and
QDs, both of which are major building blocks of graphene-based
electronics. It is well known that electronic transport in graphene
junctions and QDs are strongly dependent on their structural
characteristics, such as the contact geometry, width, edge shape,
connection angle, and so on. To the best of our knowledge, the
corresponding knowledge on the influence of these structural
freedoms on thermal-transport properties is, though of highly
importance for designing graphene devices, still missing. Several
theoretical and experimental works have been done on thermal
transport in 2D graphene sheet or individual GNRs. However, the
realisticgraphene-basednanodeviceshavemorecomplexstructures
and thus their thermal-transport properties cannot be deduced
solely from those of the regular graphene sheet or GNRs. This
motivates us to systematically study the influence of structural
characteristicsonthermaltransportingraphenejunctionsandQDs.
Here thermal conductance contributed by electrons is not
considered, because of two reasons: (i) this contribution can be
evaluated by the well known electronic transport properties, be-
cause thermal conductance and electronic conductance contributed
by electron satisfy the Wiedemann-Frantz law; and (ii) thermal
