Environmental Engineering Reference
In-Depth Information
Figure 3.18
(a) Schematics of graphene quantum dots carved from 18-
ZGNR. The width of the narrow constrictions increases from “QD1” to
“QD4”. (b) Thermal conductance (
σ
) and (c) thermal conductance ratio
(
) between quantum dots and the pristine 18-ZGNR as a function of
temperature [51].
η
leads (i.e., pristine GNR). As shown in Fig. 3.18c,
η
decreases rapidly
as the temperature increases, and becomes nearly temperature
independentathightemperatures(
>
100Kforthepresentsystems).
Theverylow
η
(evenlowerthan10%atroomtemperature)indicate
that heat dissipation in QDs will be rather slow, which may degrade
the performance of the graphene-based QD devices. On the other
hand, the extremely low thermal conductance may significantly
enhance the thermoelectric e
ciency ofQD structures.
In short summary, we systematically investigate thermal trans-
port in graphene-based nanodevices, and find that the dependence
of thermal-transport properties on the structural characteristics is
distinctlydifferentfromthatofelectronictransport.Theknowledge
andunderstandingonstructure-property relation maybeusefulfor
future applications in nanoelectronics and thermoelectricity.
