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arXiv 0901.0988cond-mat.mtrl-sci
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原始硅纳米线的热传导是强各向异性的

Heat conductance is strongly anisotropic for pristine silicon nanowires

Troels Markussen, Antti-Pekka Jauho, Mads Brandbyge

摘要:

我们原子计算的导热超薄原始硅纳米线(SiNWs)的直径范围从1到5 nm。发现室温热导率是高度各向异性的:沿着方向取向的导线<110>具有比沿着和方向取向的导线大50-75%的电导<100><111>。我们表明,各向异性可以定性地理解和再现体声子能带结构。从头计算密度泛函理论(DFT)用于研究最细的导线,但对于较大的直径,计算变得困难,我们改用Tersoff经验势模型(TEP)。对于最小的导线,从DFT和TEP计算得到的热导率在10%以内。所提出的结果可能是相关的未来纳米线器件的声子工程。

英文摘要:

We compute atomistically the heat conductance for ultra-thin pristine silicon nanowires (SiNWs) with diameters ranging from 1 to 5 nm. The room temperature thermal conductance is found to be highly anisotropic: wires oriented along the <110> direction have 50-75% larger conductance than wires oriented along the <100> and <111> directions. We show that the anisotropies can be qualitatively understood and reproduced from the bulk phonon band structure. Ab initio density functional theory (DFT) is used to study the thinnest wires, but becomes computationally prohibitive for larger diameters, where we instead use the Tersoff empirical potential model (TEP). For the smallest wires, the thermal conductances obtained from DFT- and TEP calculations agree within 10%. The presented results could be relevant for future phonon-engineering of nanowire devices.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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