Affiliation:
1. Key Laboratory of Radiation Physics and Technology Ministry of Education Institute of Nuclear Science and Technology Sichuan University Chengdu 610064 P. R. China
2. Institute of New Energy and Low‐Carbon Technology Sichuan University Chengdu 610065 P. R. China
Abstract
AbstractChemical doping of sodium is an indispensable means to optimize thermoelectric properties of PbTe materials, while a bottleneck is that an aliovalent atom doping leads to spontaneous intrinsic defects in the PbTe matrix, resulting in low dopant solubility. Therefore, it is urgent to improve the doping efficiency of Na for maximizing optimization. Here, an amazing new insight that the intentionally introduced Pb vacancies can promote Na solubility in ternary Pb1‐xNaxTe is reported. Experimental analysis and theoretical calculations provide new insights into the inherent mechanism of the enhancement of Na solubility. The Pb vacancies and the resultant more dissolved Na not only synergistically optimize the carrier concentration and further facilitate the band convergence, but also induce a large number of dense dislocations in the grains. Consequently, benefiting from the self‐enhancement of Seebeck coefficient and the minimization of lattice thermal conductivity, an 18% growth is obtained for the figure of merit zT in vacancy‐containing Pb0.95Na0.04Te sample, reaching maximum zTmax ≈ 2.0 at 823 K, which achieves an ultra‐high performance in only Na‐doped ternary Pb1‐xNaxTe materials. The strategy utilized here provides a novel route to optimize PbTe materials and represents an important step forward in manipulating thermoelectrics to improve dopant solubility.
Funder
National Key Research and Development Program of China
Chinese Academy of Sciences
Subject
Biomaterials,Biotechnology,General Materials Science,General Chemistry
Cited by
8 articles.
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