This clearly shows that the assumption of no defects overestimates the thermal conductance of SiNW and thus understanding of the effects of defects is essential for the thermal transport of SiNW. Actually, the phonon-phonon scatterings due to anharmonic effects are not important for SiNWs with diameters smaller than 30 nm [3]. Then, for one of the simplest defects, we introduce a single vacancy. Markussen et al. have studied the effect of surface vacancy defects by taking sample average of SiNWs with randomly placed surface vacancies [16, 17]. Here we focus on the effect of a vacancy at different positions on the thermal conductance.

Figure 5 Thermal conductance INCB018424 ic50 and transmission coefficients of SiNW with defects. (top) Atomistic models of 〈100〉 SiNW with 2 nm in diameter with no defects (top-left), a surface S3I-201 clinical trial defect (top-middle), and a center defect (top-right). The wire is oriented LY3009104 datasheet along the perpendicular direction to the sheet. (bottom-left)

Temperature dependence of thermal conductance of SiNWs with no defects (black lines), a surface defect (blue lines), and a center defect (red lines), for various diameters of D=1.0 nm (solid lines), D=1.5 nm (dashed lines), and D=2.0 nm (dotted lines), respectively. (bottom-right) Transmission coefficients of the SiNWs with no defects (black lines), a surface defect (blue lines), and a center defect (red lines), respectively, for 1.0 nm in diameter. Digestive enzyme The bottom-left panel of Figure 5 shows the temperature dependence of the thermal conductance with no defects, with a surface defect, and with a center defect for three diameters D = 1.0, 1.5, and 2.0 nm. Since the phonon-phonon scatterings due to anharmonic effects are not taken into account here, the thermal conductance drop observed in the high temperature

regime in experiments [1] for a thick SiNW with a diameter larger than 30 nm is not reproduced and is different from the previous work [3]. As for the effects of vacancy defects on the thermal conductance, we can see that for all diameters of SiNWs and all temperature regions, the pristine wire has the highest thermal conductance, and the vacancy effects are more significant for a center defect than for a surface defect. It would be interesting to investigate why the SiNWs have different thermal conductances when defects are included at different positions. It looks like the effects of vacancy defects on the thermal conductance are not simple, since we cannot estimate the behaviors only from the density of vacancy defects. To understand the effects of vacancy defects, we have to take the calculated results of atomistic transmission functions into account. The bottom-right panel of Figure 5 shows the transmission coefficients ζ(ω) for the SiNWs with 1.