Environmental Engineering Reference
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Figure 3.16 (a) Phonon transmission as a function of frequency ω and (b)
thermal conductance as a function of temperature T for pristine 8-ZGNR
(black solid line), “Z8-Z18” (red dashed line), “Z18-Z8-Z18” (blue dotted
line) and “Z8-Z18-Z8” (cyan dash-dotted line), (c) Schematics showing the
phonon local density of state at
900 cm 1 for “Z8-Z18”, “Z18-Z8-
Z18” and “Z8-Z18-Z8” structures. Red (blue) color represents the largest
(smallest) value [51].
ω =
interface.Toacrossthisadditionalinterface,phononsinthedouble-
interface junction transmit from the narrow GNR into the wide
GNR, different from those in the QD. Due to the strong direction-
dependenceofinterfacescattering,phononscatteringintroducedby
the second interface is small in the double-interface junction but
large in the QD. As evident, phonon transmission of the double-
interface junction is slightly lower than that of the single-interface
junction, but apparently larger than that of the QD in almost
all the frequency range especially at low-frequency region (Fig.
3.16a). Consequently, thermal conductance of graphene junctions is
significantly higher than that of the QD in the whole temperature
range (Fig.3.16b).
 
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