Carbon-Based Materials for Thermoelectrics

Figure 5

(a) Schematics of the lattice structures of graphene and graphene nanoribbon. (b) Defect density dependence of the thermal conductivity of suspended graphene [74]. The inset shows ZT of defected graphene normalized by that of pristine graphene with respect to D/G at room temperature. D/G ratio is used in Raman spectroscopy to denote the defect density. (c)–(e) The vibrational density of states, phonon participation ratio, and spatial distribution of localized modes in bulk graphene, aGNR, and zGNR [56]. In particular, the height in (e) corresponds to the magnitude of localization at that position. (f) Schematic of edge-disordered zGNR of length L sandwiched between two semiinfinite pristine zGNRs. ((g) and (h)) Phonon transmission and electron conductance for pristine and edge-disordered zGNR with a width of 20 dimer lines, respectively [75]. Panels (c)–(h) are reproduced with permission [56, 75].