Delgado Daniela, Moris Silvana, Valencia-Gálvez Paulina, López María Luisa, Álvarez-Serrano Inmaculada, Blake Graeme R, Galdámez Antonio
Departamento de Química, Facultad de Ciencias, Universidad de Chile, Las Palmeras 3425, Santiago 7800003, Chile.
Centro de Investigación de Estudios Avanzados del Maule (CIEAM), Vicerrectoría de Investigación y Postgrado, Universidad Católica del Maule, Avenida San Miguel 3605, Talca 3480112, Chile.
Materials (Basel). 2023 Jul 25;16(15):5213. doi: 10.3390/ma16155213.
Herein, we report the synthesis, structural and microstructural characterization, and thermoelectric properties of AgSn[SbBi]Te and Br-doped telluride systems. These compounds were prepared by solid-state reaction at high temperature. Powder X-ray diffraction data reveal that these samples exhibit crystal structures related to the NaCl-type lattice. The microstructures and morphologies are investigated by scanning electron microscopy, energy-dispersive X-ray spectroscopy (EDS), and high-resolution transmission electron microscopy (HRTEM). Positive values of the Seebeck coefficient (S) indicate that the transport properties are dominated by holes. The S of undoped AgSn[SbBi]Te ranges from +40 to 57 μV·K. Br-doped samples with = 2 show S values of +74 μV·K at RT, and the Seebeck coefficient increases almost linearly with increasing temperature. The total thermal conductivity () monotonically increases with increasing temperature (10-300 K). The values of undoped AgSn[SbBi]Te are ~1.8 W m K ( = 4) and ~1.0 W m K ( = 2) at 300 K. The electrical conductivity () decreases almost linearly with increasing temperature, indicating metal-like behavior. The ZT value increases as a function of temperature. A maximum ZT value of ~0.07 is achieved at room temperature for the Br-doped phase with = 4.
在此，我们报道了AgSn[SbBi]Te和Br掺杂碲化物体系的合成、结构与微观结构表征以及热电性能。这些化合物通过高温固相反应制备。粉末X射线衍射数据表明，这些样品呈现出与NaCl型晶格相关的晶体结构。通过扫描电子显微镜、能量色散X射线光谱（EDS）和高分辨率透射电子显微镜（HRTEM）研究了微观结构和形貌。塞贝克系数（S）的正值表明传输性质以空穴为主导。未掺杂的AgSn[SbBi]Te的S值范围为 +40至57 μV·K。Br掺杂量为 = 2的样品在室温下的S值为 +74 μV·K，并且塞贝克系数几乎随温度升高呈线性增加。总热导率（）随温度升高（10 - 300 K）单调增加。未掺杂的AgSn[SbBi]Te在300 K时的 值分别为1.8 W m K（ = 4）和1.0 W m K（ = 2）。电导率（）几乎随温度升高呈线性下降，表明具有类金属行为。ZT值随温度升高而增加。对于Br掺杂量为 = 4的相，在室温下实现了约0.07的最大ZT值。
