Electrical transport and thermoelectric properties of boron carbide nanowires
Electrical transport and thermoelectric properties of boron carbide nanowires
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DOI：
10.1088/1361-6528/aa610c
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发表时间：
2017-03
期刊：
影响因子：
3.5
通讯作者：
K. Kirihara;M. Mukaida;Y. Shimizu
中科院分区：
文献类型：
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作者：
K. Kirihara;M. Mukaida;Y. Shimizu
报道了用碳热法合成的碳化硼纳米线的电输运和热电性能。结果表明，纳米线实现了更高的塞贝克系数和功率因数比那些块体样品。在低于300 K的低温下的纳米线的导电机制是不同的烧结多晶和单晶体样品。在200-450 K的温度范围内，通过可变范围跳跃和声子辅助跳跃的导电之间存在交叉。纳米线中的不均匀碳浓度和平面缺陷（例如孪晶和堆垛层错）被认为显著地改变了碳化硼晶体的键合性质和电子结构，导致电导率和塞贝克系数的差异。讨论了声子在纳米结构表面的边界散射对热导率降低的影响。
The electrical transport and thermoelectric property of boron carbide nanowires synthesized by a carbothermal method are reported. It is demonstrated that the nanowires achieve a higher Seebeck coefficient and power factor than those of the bulk samples. The conduction mechanism of the nanowires at low temperatures below 300 K is different from that of the sintered-polycrystalline and single-crystal bulk samples. In a temperature range of 200–450 K, there is a crossover between electrical conduction by variable-range hopping and phonon-assisted hopping. The inhomogeneous carbon concentration and planar defects, such as twins and stacking faults, in the nanowires are thought to modify the bonding nature and electronic structure of the boron carbide crystal substantially, causing differences in the electrical conductivity and Seebeck coefficient. The effect of boundary scattering of phonon at nanostructured surface on the thermal conductivity reduction is discussed.