Kim Dong Ho, Kim TaeWan, Lee Se Woong, Kim Hyun-Sik, Shin Weon Ho, Kim Sang-Il
Departament of Materials Science and Engineering, University of Seoul, Seoul 02504, Korea.
Departament of Electrical Engineering and Smart Grid Research Center, Jeonbuk National University, Jeonju 54896, Korea.
Materials (Basel). 2021 Dec 9;14(24):7567. doi: 10.3390/ma14247567.
One means of enhancing the performance of thermoelectric materials is to generate secondary nanoprecipitates of metallic or semiconducting properties in a thermoelectric matrix, to form proper band bending and, in turn, to induce a low-energy carrier filtering effect. However, forming nanocomposites is challenging, and proper band bending relationships with secondary phases are largely unknown. Herein, we investigate the in situ phase segregation behavior during melt spinning with various metal elements, including Ti, V, Nb, Mo, W, Ni, Pd, and Cu, in -type BiSbTe (BST) thermoelectric alloys. The results showed that various metal chalcogenides were formed, which were related to the added metal elements as secondary phases. The electrical conductivity, Seebeck coefficient, and thermal conductivity of the BST composite with various secondary phases were measured and compared with those of pristine BST alloys. Possible band alignments with the secondary phases are introduced, which could be utilized for further investigation of a possible carrier filtering effect when forming nanocomposites.
提高热电材料性能的一种方法是在热电基体中生成具有金属或半导体性质的二次纳米沉淀物，以形成适当的能带弯曲，进而诱导低能量载流子过滤效应。然而，形成纳米复合材料具有挑战性，并且二次相的适当能带弯曲关系在很大程度上尚不清楚。在此，我们研究了在熔体纺丝过程中，包括Ti、V、Nb、Mo、W、Ni、Pd和Cu在内的各种金属元素在 -型BiSbTe（BST）热电合金中的原位相分离行为。结果表明，形成了各种金属硫族化物，它们作为二次相与添加的金属元素有关。测量了具有各种二次相的BST复合材料的电导率、塞贝克系数和热导率，并与原始BST合金的进行了比较。介绍了与二次相可能的能带排列，这可用于在形成纳米复合材料时进一步研究可能的载流子过滤效应。
