Zn空位对Zn-Sb Zintl相热电材料的热输运和电输运有重要影响。本文采用快速感应熔炼和真空热压法制备了p型Mg1.77CuxZn1.2−0.5xAg0.03Sb2 (x = 0, 0.02, 0.05, 0.08, 0.1)样品,研究了Zn空位上的异价铜取代对样品热电性能的影响。实验结果表明,在低掺杂浓度下(x 1.77Cu0.05Zn1.175Ag0.03Sb2样品在673 K时得到了最大zT值为0.60,相比于未掺杂Cu样品的zT值提升了33%。我们的研究表明,用异价Cu调控Zn空位是提高p型Mg3Sb2基材料热电性能的有效策略。Zn vacancies have been proposed to have significant impacts on thermal and electronic transport for Zn-Sb Zintl phase materials. In this work, we investigated the effect of aliovalent Cu substitution at Zn vacancies on thermoelectric performance in p-type Mg1.77CuxZn1.2−0.5xAg0.03Sb2 (x = 0, 0.02, 0.05, 0.08, 0.1) samples prepared by rapid induction melting and hot pressing. Experimental results revealed that Cu atoms preferentially occupy the Zn vacancies to decrease the carrier concentration at low concentrations of doping (x zT value of 0.60 is discovered at 673 K for the Mg1.77Cu0.05Zn1.175Ag0.03Sb2 sample, which is 33% higher than that of the undoped Cu sample. Our research indicates that manipulating Zn vacancies with aliovalent Cu is a useful tactic for enhancing the thermoelectric performance of p-type Mg3Sb2-based materials.
