Sb掺杂对N型half-Heusler材料热电性能的影响

研究了Sb掺杂对N型half-Heusler化合物Zr_0.25Hf_0.25Ti_0.5NiSn_1-xSb_x (x=0、0.002、0.005、0.01、0.02、0.03)热电传输特性的影响。结果显示, 随着Sb掺杂量增加, 材料的载流子浓度提高, 电阻率降低, 尤其是低温(<300 K)电阻率下降显著, 赛贝克系数降低, 且取得最大赛贝克系数的温度向高温端移动, 最大功率因子增加~20%, 材料的热导率增大, 主要是电子热导率提高的贡献, 晶格热导率影响不大; 当Sb掺杂量较低时(x<0.01), 材料的最大热电性能优值ZT值在0.77左右, 掺杂量x=0.005的样品ZT值在整个温度区间内最优。

Effect of Sb Doping on Thermoelectric Property of N-type Half-Heusler Compounds

The effect of Sb doping on thermoelectric transport properties of N-type half-Heusler compounds Zr_0.25Hf_0.25Ti_0.5NiSn_1-xSb_x (x=0, 0.002, 0.005, 0.01, 0.02, 0.03) was studied. Results show that with increasing Sb doping amount, the carrier concentration of the samples increases while the electrical resistivity decreases, especially sharply at low temperature range (~300 K). The Seebeck coefficient decreases, and the temperatures at which the Seebeck coefficient reaches climax move to higher ones. Therefore, the power factor increases by ~20%. The total thermal conductivity increases mainly due to the enhancement of electrical thermal conductivity, the lattice thermal conductivity remains almost unchanged. For the samples with x<0.01, the maximum ZT value is about 0.77 at 800 K, and among the samples, the one with x=0.005 performs the best in the whole temperature range.