Remarkable Roles of Cu To Synergistically Optimize Phonon and Carrier Transport in n-Type PbTe-Cu2Te
Remarkable Roles of Cu To Synergistically Optimize Phonon and Carrier Transport in n-Type PbTe-Cu2Te
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Cu 在协同优化 n 型 PbTe-Cu2Te 中声子和载流子传输方面的显着作用
DOI：
10.1021/jacs.7b11662
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发表时间：
2017
影响因子：
15
通讯作者：
Zhao Li-Dong
中科院分区：
文献类型：
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作者：
Xiao Yu;Wu Haijun;Li Wei;Yin Meijie;Pei Yanling;Zhang Yang;Fu Liangwei;Chen Yuexing;Pennycook Stephen J.;Huang Li;He Jiaqing;Zhao Li-Dong
迫切需要高热电性能的n型PbTe来匹配p型PbTe。在这里，我们展示了在723 K时峰值zt ~ 1.5，在300-873 K时，通过引入Cu2Te夹杂物协同抑制晶格热导率和提高载流子迁移率，在n型PbTe中实现了创纪录的高平均zt bbb1.0。Cu发挥了几个突出的作用：Cu原子填补Pb空位并提高载流子迁移率，有助于在423 K时获得意想不到的高功率因数~ 37 μW cm-1K-2at；在PbTe-5.5%Cu2Te中，填充Pb空位和Cu间隙的Cu原子都会引起局部无序，并与纳米和微尺度富Cu沉淀及其相关的应变场一起，导致晶格热导率非常低，为~ 0.38 Wm-1K-1，接近理论最小值~ 0.36 Wm-1K-1。这项工作提供了一个有效的策略，以提高热电性能，同时改善电和热输运性质。
High thermoelectric performance of n-type PbTe is urgently needed to match its p-type counterpart. Here, we show a peakZT∼ 1.5 at 723 K and a record high averageZT> 1.0 at 300–873 K realized in n-type PbTe by synergistically suppressing lattice thermal conductivity and enhancing carrier mobility by introducing Cu2Te inclusions. Cu performs several outstanding roles: Cu atoms fill the Pb vacancies and improve carrier mobility, contributing to an unexpectedly high power factor of ∼37 μW cm–1K–2at 423 K; Cu atoms filling Pb vacancies and Cu interstitials both induce local disorder and, together with nano- and microscale Cu-rich precipitates and their related strain fields, lead to a very low lattice thermal conductivity of ∼0.38 Wm–1K–1in PbTe-5.5%Cu2Te, approaching the theoretical minimum value of ∼0.36 Wm–1K–1. This work provides an effective strategy to enhance thermoelectric performance by simultaneously improving electrical and thermal transport properties.