High Thermoelectric Performance SnTe-In2Te3 Solid Solutions Enabled by Resonant Levels and Strong Vacancy Phonon Scattering
High Thermoelectric Performance SnTe-In2Te3 Solid Solutions Enabled by Resonant Levels and Strong Vacancy Phonon Scattering
复制标题
DOI：
10.1021/acs.chemmater.5b03708
复制
发表时间：
2015-11
影响因子：
8.6
通讯作者：
G. Tan;W. Zeier;F. Shi;Pengli Wang;G. J. Snyder;V. Dravid;M. Kanatzidis
中科院分区：
文献类型：
--
作者：
G. Tan;W. Zeier;F. Shi;Pengli Wang;G. J. Snyder;V. Dravid;M. Kanatzidis
在这里，我们报告了一个显着改善的热电优值系数ZT为1.1，在923 K的p型SnTe通过In 2 Te 3合金化和碘掺杂。我们建议，在锡锡网站在SnTe中的铟的引入创建价带内的共振能级，从而大大增加塞贝克系数和功率因数在低到中温度范围内。与SnTe-InTe不同，SnTe-In 2 Te 3系统显示出低得多的晶格热导率。利用点缺陷散射模型，我们分析了SnTe-In_2 Te_3中低热导率的起源，并将其主要归因于Sn原子和In_2 Te_3合金化引入的空位之间的强空位起源声子散射，部分归因于SnTe基体中存在的富In纳米沉淀物的界面散射。通过仅将In 2 Te 3与SnTe合金化，在923 K下实现了ZT值为0.9。在923 K时，通过在Te位掺杂碘来调节载流子，ZT可进一步提高到1.1。
Herein, we report a significantly improved thermoelectric figure of merit ZT of ∼1.1 at ∼923 K in p-type SnTe through In2Te3 alloying and iodine doping. We propose that the introduction of indium at Sn sites in SnTe creates resonant levels inside the valence bands, thereby considerably increasing the Seebeck coefficients and power factors in the low-to-middle temperature range. Unlike SnTe–InTe, the SnTe–In2Te3 system displays much lower lattice thermal conductivity. Utilizing a model for point defect scattering, we analyze the origin of the low thermal conductivity in SnTe–In2Te3 and attribute it mainly to the strong vacancy originated phonon scattering between Sn atoms and the vacancies introduced by In2Te3 alloying and partly to the interfacial scattering by In-rich nanoprecipitates present in SnTe matrix. By alloying only In2Te3 with SnTe, a ZT value of ∼0.9 at 923 K was achieved. ZT can be further increased to ∼1.1 at 923 K through adjusting the charge carriers by iodine doping at Te sites.