Developments of environment-friendly semiconductor clathrate for thermoelectric materials and their thermoelectric generator devices

2015 Fiscal Year Final Research Report

• Project/Area Number: 25420763
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Structural/Functional materials
• Research Institution: Tokyo University of Science, Yamaguchi
• Principal Investigator: ANNO Hiroaki 山口東京理科大学, 工学部, 教授 (60279106)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 未利用熱利用 / 熱電変換 / ゼーベック効果 / シリコン / クラスレート / 同時ドーピング / 熱電的特性 / 機械的特性

Outline of Final Research Achievements

In order to improve the thermoelectric figure of merit for a thermoelectric silicon-based clathrate system, an environment-friendly semiconductor system, we investigated the optimization of the silicon-based clathrate system by a codoping approach, and revealed the effect of parameters of codoping, such as combinations of codoping elements and doping level, on the thermoelectric properties for silicon-based clathrate system. We succeeded in improving the thermoelectric performance by a factor of 17 %, compared to previous value, by the codoping approach. Moreover, we investigated in detail the thermal stability in air, oxidation resistance, elastic properties, and mechanical properties, such as the fracture toughness, Vickers hardness, which were not known for silicon-based clathrate system. Consequently, it was found that silicon-based clathrate system had good thermal stability in air, high oxidation resistance, and sufficient mechanical strength for thermoelectric applications.

Free Research Field

電子材料工学、熱電変換工学、電子デバイス工学