MnTeと重合金されたSnTeの値帯改変と高熱電気性能
Gangjian Tan1, Fengyuan Shi2, Shiqiang Hao2
1Department of Chemistry, Northwestern University , Evanston, Illinois 60208, United States.
Journal of the American Chemical Society
|August 27, 2015
まとめ
タンテル化物 (SnTe) をマンガンテル化物 (MnTe) と合金することで高熱電性能を達成しました. このドーピングはシーベック係数を高め 熱伝導性を低下させ エネルギー変換の効率を高めます
科学分野:
- 材料科学
- 凝縮物質物理学
- ナノテクノロジー
背景:
- チンテルリド (SnTe) は有望な熱電性材料ですが,性能を向上させるために最適化が必要です.
- カドミウム (Cd) や水銀 (Hg) のような元素でSnTeをドーピングすることは,溶解性の限界が低いため,限られた成功を収めている.
研究 の 目的:
- タンテルリド (SnTe) とマンガンテルリド (MnTe) を合金することで,その熱電特性への影響を調査する.
- 熱電性能の改善のための高マンガネステロリド (MnTe) ドーピングの可能性を調査する.
主な方法:
- SnTeとMnTeを9mol%を超える溶解度まで合金する.
- 電気伝導率,シーベック係数,ホール効果を温度範囲で測定する.
- 密度関数理論 (DFT) に基づく最初の原理の電子構造計算を用いる.
主要な成果:
- MnTeはSnTeで9mol%以上の高溶解度に達した.
- シーベック係数とパワーファクターの有意な増加は,MnTeの含有量増加に伴います.
- 高いMnドーピングにより,900Kで~230μV/Kのシーベック係数を導いたバレンスの帯間の収束が実証された.
- フォノン散乱の強化により800Kで0.9Wm−1K−1の低格子熱伝導性が報告されました.
- 900Kで1.3の高い熱電性値 (ZT) を達成した.
結論:
- SnTeに高いMnTeをドーピングすると,電子帯の構造が効果的に変化し,熱電気的性質が強化されます.
- 電子とフォノン輸送に対するMnドーピングの相乗効果は,優れた熱電性能をもたらします.
- この研究は,SnTeベースの熱電学を実用的なアプリケーションに最適化するための実行可能な戦略を提示しています.
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