PbTe纳米晶高压热电性能的研究

 利用自建的400 t四柱双缸液压机，研究了PbTe纳米晶在0~0.8 GPa压力范围内热电性能随压力的变化。实验结果表明：PbTe纳米晶电导率随压力的增加而增加，而热电动势随压力的增加而减小，两者随压力的变化具有可逆性；PbTe纳米晶具有极高的热电动势，在常压下达到565 μV/K，在0.8 GPa压力下，材料的电导率为常压下的4倍，热电动势仅降低20%，功率因子则达到常压下的3倍。研究表明，高压能显著提高PbTe纳米晶的热电性能。利用第一性原理计算了0.4~4.0 GPa压力范围内材料的简约费米能级，计算结果与实验结果相吻合。

Thermoelectric Properties of Nanoparticle PbTe under Hydrostatic Pressure

The thermoelectric properties of PbTe nanoparticles were studied from ambient pressure to 0.8 GPa by using self-built set-up.The electrical conductivity increased while Seebeck coefficient decreased with loading pressure and these properties can be recovered after pressure released.Moreover,Seebeck coefficient is extremely high,up to 565 μV/K at ambient pressure.At 0.8 GPa,the electrical conductivity enhances four times,the power factor adds three times and Seebeck coefficient is only reduced by 20% comparing with those at ambient pressure.These results indicate that high pressure can improve the thermoelectric properties of PbTe nanoparticle.The contracted Femi-energy is also calculated based on the First Principle under high pressure from 0.4 to 4.0 GPa.The calculated values agree well with experimental data.