K2Bi8Se13の複数の収束伝導帯:非常に低い熱伝導性を有する有望な熱電気材料
Yanling Pei1, Cheng Chang1, Zhe Wang2,3
1School of Materials Science and Engineering, Beihang University , Beijing 100191, China.
Journal of the American Chemical Society
|December 13, 2016
まとめ
カリウムビスムートセレニド (K2Bi8Se13) は,複数の伝導帯と低熱伝導性により熱電性能が向上しています. ドーピングはシーベック係数を高め,873Kで高いZT値を達成します.
科学分野:
- 材料科学
- 凝縮物質物理学
- 熱電機
背景:
- 熱電気材料は廃棄熱の回収と固体冷却に不可欠です.
- 熱電性能を最適化するには,同時に電気的性質を向上させ,熱伝導性を最小限に抑える必要があります.
- カリウムビスムートセレニド (K2Bi8Se13) は,複雑な結晶構造を持つ有望な熱電性物質である.
研究 の 目的:
- K2Bi8Se13の熱電性について調べるため
- 電子帯構造,結晶構造,熱伝導の関係を理解する.
- ドーピングを通して熱電動値 (ZT) を最適化します.
主な方法:
- K2Bi8Se13の合成と特徴付け
- 温度に依存する電気および熱伝送測定
- フォノン速度の測定,電子 difraktion,および伝送電子顕微鏡.
- 微細構造分析で 副次的な段階を特定する
主要な成果:
- K2Bi8Se13はドーピングによって活性化され,シーベック係数とパワーファクターを高める複数の,密接な伝導帯を示しています.
- 複雑な構造と結合に起因する低格子熱伝導度 (0.420.20 W m−1 K−1).
- フォノン速度の測定は低熱伝導性を確認し,低平均フォノン速率,ヤングのモジュール,デバイ温度を示した.
- 電子ドーピングされたK2Bi8Se13は873Kで約1. 3の高いZT値を達成した.
結論:
- K2Bi8Se13のドーピングは,熱電気的パワーファクターを効果的に高めます.
- K2Bi8Se13の固有の低格子熱伝導性は,高いZTの重要な要因である.
- この材料は,効率的な熱電気エネルギー変換アプリケーションのための大きな可能性を示しています.
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