Tan Ming, Hao Yanming, Deng Yuan, Yan Dali, Wu Zehua
Department of Physics, College of Sciences, Tianjin University of Science & Technology, Tianjin, 300457, China.
Beijing Key Laboratory of Special Functional Materials and Films, School of Materials Science and Engineering, Beihang University, Beijing, 100191, China.
Sci Rep. 2018 Apr 23;8(1):6384. doi: 10.1038/s41598-018-24872-4.
The uniquely tilted nanopillar array favorably influence carrier and phonon transport properties. We present an innovative interfacial design concept and a novel tilt-structure of hierarchical BiSbTe nanopillar array comprising unique interfaces from nano-scaled open gaps to coherent grain boundaries, and tilted nanopillars assembled by high-quality nanowires with well oriented growth, utilizing a simple vacuum thermal evaporation technique. The unusual structure BiSbTe nanopillar array with a tilt angle of 45° exhibits a high thermoelectric performance ZT = 1.61 at room temperature. The relatively high ZT value in contrast to that of previously reported BiSbTe materials and the BiSbTe nanopillar array with a tilt angle of 60° or 90° evidently reveals the crucial role of the unique interface and tilt-structure in favorably influencing carrier and phonon transport properties, resulting in a significantly improved ZT value. This method opens a new approach to optimize nano-structure film materials.
独特倾斜的纳米柱阵列对载流子和声子输运特性产生有利影响。我们提出了一种创新的界面设计概念以及一种新型的分级BiSbTe纳米柱阵列倾斜结构，该结构包含从纳米级开放间隙到相干晶界的独特界面，并且通过具有良好取向生长的高质量纳米线组装而成倾斜纳米柱，采用的是简单的真空热蒸发技术。倾斜角为45°的异常结构BiSbTe纳米柱阵列在室温下表现出高热电性能ZT = 1.61。与先前报道的BiSbTe材料以及倾斜角为60°或90°的BiSbTe纳米柱阵列相比，相对较高的ZT值明显揭示了独特界面和倾斜结构在有利影响载流子和声子输运特性方面的关键作用，从而导致ZT值显著提高。该方法为优化纳米结构薄膜材料开辟了一条新途径。
