Multifaceted analysis and design of thermoelectric clathrate materials based on single crystals

2022 Fiscal Year Final Research Report

• Project/Area Number: 21K20489
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund
• Review Section: 0401:Materials engineering, chemical engineering, and related fields
• Research Institution: Kyushu University
• Principal Investigator: Matsukawa Yuko 九州大学, 工学研究院, 助教 (00910217)
• Project Period (FY): 2021-08-30 – 2023-03-31
• Keywords: 熱電材料 / クラスレート化合物 / チョクラルスキー法 / 単結晶化 / 粒成長

Outline of Final Research Achievements

Ba8CuxSi46－x, Ba8CuxGe46－x, and Sr8AlxGa16－xSi30 clathrate semiconductors were successfully fabricated via Czochralski method. The specimens exhibiting refined composition and enhanced performance were derived from starting material whose compositions were tailored. The single crystallization technique yielded a reduced density of grain boundaries within the specimens, leading to the lower resistivity. The incorporation of additional elements into the initial material and annealing process following the Choklarsky method improved sample stability and performance by reducing impurities.

Free Research Field

材料工学

Academic Significance and Societal Importance of the Research Achievements

本研究は、資源的・環境負荷的制約が小さいクラスレート熱電材料において、実用化の目安を満たすp型の熱電材料を実現した。このことは、社会の様々な場面での熱電材料の応用を加速させる可能性がある。また作製した材料中の、不純物が材料の安定性や性能に与え得る影響を報告し、その対策を開発したことは、学術的にも社会実装的にも重要となる単相および単結晶試料の作製に資すると期待される。