论文部分内容阅读
利用高能球磨和快速直流热压技术制备并研究了Al元素对Bi2Te2.7Se0.3合金热电性能的影响。Al的掺杂提高了材料的Seebeck系数和功率因子。Bi2Te2.7Se0.3Al0.02的Seebeck系数在423 K时达到了200μV·K-1,功率因子在323 K时达到了2410μW·m-1·K-2,相比同温度下未掺杂的样品分别提高了约40%和19%;同时,纳米晶粒之间的晶界对声子散射显著降低了晶格热导率,使Bi2Te2.7Se0.3Al0.02的总热导率在323 K达到0.85 W·m-1·K-1,比同温度下未掺杂样品降低了33%。功率因子的提高和热导率的降低使材料的热电优值ZT在373 K时达到了0.97。
The effect of Al element on the thermoelectric properties of Bi2Te2.7Se0.3 alloy was investigated by high energy ball milling and rapid DC hot pressing. Al doping increases the Seebeck coefficient and power factor of the material. The Seebeck coefficient of Bi2Te2.7Se0.3Al0.02 reached 200μV · K-1 at 423 K, and the power factor reached 2410μW · m-1 · K-2 at 323 K. Compared with the undoped sample Respectively, by about 40% and 19% respectively. At the same time, the grain boundary phonon scattering between nanocrystalline grains significantly reduces the thermal conductivity of the crystal lattice, so that the total thermal conductivity of Bi2Te2.7Se0.3Al0.02 reached at 323 K 0.85 W · m-1 · K-1, which is 33% lower than that of undoped samples at the same temperature. The increase of power factor and the decrease of thermal conductivity make the thermoelectric figure of merit ZT reach 0.97 at 373K.