Conduction mechanism and thermoelectric properties of new boron carbide nanowires as a novel thermoelectric material

2016 Fiscal Year Final Research Report

• Project/Area Number: 25286028
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Nanomaterials engineering
• Research Institution: National Institute of Advanced Industrial Science and Technology
• Principal Investigator: Kirihara Kazuhiro 国立研究開発法人産業技術総合研究所, ナノ材料研究部門, 主任研究員 (70392610)
• Co-Investigator(Kenkyū-buntansha): 向田 雅一 国立研究開発法人産業技術総合研究所, ナノ材料研究部門, 主任研究員 (70358141)
• Co-Investigator(Renkei-kenkyūsha): SHIMIZU Yoshiki 産業技術総合研究所, ナノ材料研究部門, 研究グループ長 (20371049)
• Project Period (FY): 2013-04-01 – 2017-03-31
• Keywords: ナノ材料 / 熱電変換 / ナノ物性計測 / 炭化ホウ素

Outline of Final Research Achievements

Boron carbide is a promising candidate of thermoelectric (TE) materials which generate electric power from the enormous amount of unused waste heat. In this research, we successfully synthesized boron carbide nanowires (BCNWs) and measured their electrical transport and thermoelectric properties. We found that the BCNW achieved a higher Seebeck coefficient and power factor than those of the bulk sample. The conduction mechanism of the BCNWs at low temperatures below 300 K is different from that of the bulk sample. At around 300 K, there is a crossover temperature between electrical conduction by variable-range hopping and phonon-assisted hopping. The inhomogeneous carbon concentration and planar defects are thought to modify the bonding nature and electronic structure of the BCNW. A lightweight and high-strength TE module by using the BCNWs that possess higher TE performance than the bulk materials can be expected.

Free Research Field

ナノ材料科学