文章基本信息

标题：Superior intrinsic thermoelectric performance with zT of 1.8 in single-crystal and melt-quenched highly dense Cu2-xSe bulks
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作者：Lan-ling Zhao ; Xiao-lin Wang ; Ji-yang Wang 等
期刊名称：Scientific Reports
电子版ISSN：2045-2322
出版年度：2015
卷号：5
期号：1
DOI：10.1038/srep07671
语种：English
出版社：Springer Nature
摘要：Practical applications of the high temperature thermoelectric materials developed so far are partially obstructed by the costly and complicated fabrication process. In this work, we put forward two additional important properties for thermoelectric materials, high crystal symmetry and congruent melting. We propose that the recently discovered thermoelectric material Cu_{2- x}Se, with figure of merit, zT , over 1.5 at T of ~ 1000 K, should meet these requirements, based on our analysis of its crystal structure and the Cu-Se binary phase diagram. We found that its excellent thermoelectric performance is intrinsic, and less dependent on grain size, while highly dense samples can be easily fabricated by a melt-quenching approach. Our results reveal that the melt-quenched samples and single crystals exhibit almost the same superior thermoelectric performance, with zT as high as 1.7–1.8 at T of ~973 K. Our findings not only provide a cheap and fast fabrication method for highly dense Cu_{2- x}Se bulks with superior thermoelectric performance, paving the way for possible commercialization of Cu_{2- x}Se as an outstanding component in practical thermoelectric modules, but also provide guidance in searching for new classes of thermoelectric systems with high crystal symmetry or further improving the cost performance of other existing congruent-melting thermoelectric materials.