Realizing High Thermoelectric Performance below Phase Transition Temperature in Polycrystalline SnSe via Lattice Anharmonicity Strengthening and Strain Engineering
Realizing High Thermoelectric Performance below Phase Transition Temperature in Polycrystalline SnSe via Lattice Anharmonicity Strengthening and Strain Engineering
复制标题
通过晶格非谐强化和应变工程在多晶 SnSe 中实现低于相变温度的高热电性能
DOI：
10.1021/acsami.8b10056
复制
发表时间：
2018-09-12
影响因子：
9.5
通讯作者：
Peng, Zhenzhen
中科院分区：
文献类型：
--
作者：
Tang, Guodong;Liu, Jiang;Peng, Zhenzhen
我们报告的高热电性能的p型多晶SnSe获得低于相变温度下利用Pb掺杂和引入Sn空位。Pb掺杂和Sn空位的引入提高了多晶SnSe的载流子浓度，从而提高了多晶SnSe的电导率和功率因数。结果表明，Pb替代和Sn空位通过形成较弱的成键而增强了晶格非谐性。我们发现Pb的替代在SnSe晶粒内部引入了巨大的应力场。通过晶格非谐强化和施加大的应力场可以大幅度降低材料的热导率。在773 K时，Sn 0.92 Pb 0.03 Se样品的晶格热导率降低到0.18 W m（-1）K-1。结果表明，通过晶格非谐强化和应变工程，Sn 0.93 Pb 0.02 Se样品在773 K时获得了接近1.4的高ZT。
We report the high thermoelectric performance of p-type polycrystalline SnSe obtained below the phase transition temperature by harnessing Pb doping and introducing Sn vacancies. The enhanced carrier concentration induced by Pb doping and introducing Sn vacancies contributes to enhancements of electrical conductivity and power factor of polycrystalline SnSe. We demonstrate that the lattice anharmonicity is strengthened by Pb substitution and Sn vacancies through forming weaker bonds. We find that Pb substitution introduces huge stress field in the interior of the SnSe grains. The thermal conductivity can be greatly reduced by lattice anharmonicity strengthening and applying huge stress field. The lattice thermal conductivity is reduced to as low as 0.18 W m(-1) K-1 in the Sn0.92Pb0.03Se sample at 773 K. As a result, a remarkable high ZT of similar to 1.4 was achieved at 773 K in the Sn0.93Pb0.02Se sample through lattice anharmonicity strengthening and strain engineering.