Anisotropic Thermoelectric Properties of n-Type Te-Free (Bi, Sb)(2)Se-3 with Orthorhombic Structure
Anisotropic Thermoelectric Properties of n-Type Te-Free (Bi, Sb)(2)Se-3 with Orthorhombic Structure
复制标题
正交结构n型无Te(Bi,Sb)(2)Se-3的各向异性热电性能
DOI：
10.1021/acsaem.9b02081
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发表时间：
2020
影响因子：
6.4
通讯作者：
Zhu Tiejun
中科院分区：
文献类型：
--
作者：
Fang Teng;Li Feng;Wu Yehao;Zhang Qi;Zhao Xinbing;Zhu Tiejun
Bi2Se3是最好的室温热电（TE） Bi2Te3的姊妹化合物，通过sb合金化，证明了Bi2Se3经历了从菱形相到正交相的转变。具有正交结构的无TE bi2 - xsbxse3在中温范围内表现出优异的TE性能。本文系统地研究了块体多晶型Bi2-xSbxSe3 （x= 0.8, 1.0）样品在相变组成附近的各向异性输运性质。由于bi2 - xsbxse3样品的电导率和导热率具有相似的各向异性，因此掺i的bi2 - xsbxse3样品在面内和面外方向上的zt值几乎相同。此外，为了进一步提高载流子迁移率和TE性能，还采用区熔法制备了n型掺杂bi2 - xsbxse3。结果表明，导热系数的增加超过了电输运性能的增强，导致zt值降低。
Bi2Se3, a sister compound of the best room-temperature thermoelectric (TE) Bi2Te3, has been proven to undergo a transition from a rhombohedral phase to an orthorhombic phase by Sb-alloying. Te-free Bi2–xSbxSe3with an orthorhombic structure exhibits excellent TE performance in the midtemperature range. In this work, anisotropic transport properties of bulk polycrystallinen-type Bi2–xSbxSe3(x= 0.8, 1.0) samples near phase transition composition are systematically studied. Due to the similar anisotropic behavior between electrical conductivity and thermal conductivity, the I-doped Bi2–xSbxSe3samples show almost the samezTvalues along the in-plane and out-of-plane directions. Furthermore,n-type I-doped Bi2–xSbxSe3is also prepared by zone-melting in order to further increase the carrier mobility and TE performance. The results show that the increase in thermal conductivity exceeds the enhancement in electrical transport properties, resulting in lowerzTvalues.