Investigation of Phase Segregation in p-Type Bi0.5Sb1.5Te3 Thermoelectric Alloys by In Situ Melt Spinning to Determine Possible Carrier Filtering Effect

Materials

TaeWan Kim¹  Weon Ho Shin²  Hyun-Sik Kim³  Se Woong Lee⁴  Sang-il Kim⁴  Dong Ho Kim⁴ 

[1] Departament of Electrical Engineering and Smart Grid Research Center, Jeonbuk National University, Jeonju 54896, Korea;Departament of Electronic Materials Engineering, Kwangwoon University, Seoul 01897, Korea;Departament of Materials Science and Engineering, Hongik University, Seoul 04066, Korea;Departament of Materials Science and Engineering, University of Seoul, Seoul 02504, Korea;

关键词: thermoelectric;    phase segregation;    melt spinning;    carrier filtering effect;   

DOI  :  10.3390/ma14247567

来源: DOAJ

【 摘 要 】

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 p-type Bi_0.5Sb_1.5Te₃ (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.

【 授权许可】

Unknown