Chen Ting-Gang, Yu Peichen, Chou Rone-Hwa, Pan Ci-Ling
Department of Photonics, Institute of Electro-Optical Engineering, National Chiao Tung University, Hsinchu, Taiwan.
Opt Express. 2010 Sep 13;18 Suppl 3:A467-76. doi: 10.1364/OE.18.00A467.
Vertically-aligned silicon nanowires (SiNWs) that demonstrate reductions of phonon thermal conductivities are ideal components for thermoelectric devices. In this paper, we present large-area silicon nanowire arrays in various lengths using a silver-induced, electroless-etching method that is applicable to both n- and p-type substrates. The measured thermal conductivities of nanowire composites are significantly reduced by up to 43%, compared to that of bulk silicon. Detailed calculations based on the series thermal resistance and phonon radiative transfer models confirm the reduction of thermal conductivity not only due to the increased air fraction, but also the nanowire size effect, suggesting the soundness of employing bulk silicon nanowire composites as efficient thermoelectric materials.
具有降低的声子热导率的垂直排列硅纳米线（SiNWs）是热电器件的理想组件。在本文中，我们使用银诱导化学蚀刻法制备了各种长度的大面积硅纳米线阵列，该方法适用于n型和p型衬底。与体硅相比，纳米线复合材料的实测热导率显著降低，降幅高达43%。基于串联热阻和声子辐射传输模型的详细计算证实，热导率的降低不仅归因于空气份额的增加，还归因于纳米线尺寸效应，这表明采用体硅纳米线复合材料作为高效热电材料是合理的。
