高性能の大量熱電器の電子帯の収束
Yanzhong Pei1, Xiaoya Shi, Aaron LaLonde
1Materials Science, California Institute of Technology, Pasadena, California 91125, USA.
Nature
|May 6, 2011
まとめ
研究者は,散発性合金におけるバレーの退化率を増やすことにより,廃棄熱の回収のための熱電気材料を強化しました. この突破は1.8の高いメリット (zT) を達成し,効率的な熱から電気への変換の道を開く.
科学分野:
- マテリアルサイエンス 材料科学
- 固体物理 固体物理学
- エネルギー変換 エネルギー変換
背景:
- 熱電気発電機は,熱を直接電気に変換し,廃棄熱回収の応用があります.
- 現在の熱電材料の効率は限られている (zT <1.5) のため,普及を妨げている.
- 電子帯域の高谷変性 (High Valley Degeneration) は,熱電効率を改善することが知られている.
研究 の 目的:
- 実践的な応用のために,1.5を超えるメリット (zT) の強化された数値を持つ新しい熱電気材料を開発する.
- 大量の熱電性材料における谷の退廃を増加させる方法を調査する.
- 散発熱電材料の改善のための一般的な戦略を実証する.
主な方法:
- トゥーニング・ドーピングと組成による大量PbTe(1-x) Se(x) 合金におけるエンジニアリングされたバンド構造.
- 電子帯域バレーの収束を達成した.
- 高温で測定された熱電特性.
主要な成果:
- ドーピングされたPbTe{1-x) Se{-x) 合金で少なくとも12の電子バレーの収束が実証されました.
- 約850ケルビンで1.8の非凡な熱電気値 (zT) を達成しました.
- シーベック係数と電気伝導性の同時改善を示した.
結論:
- バンドエンジニアリングにより,バレンス帯または伝導帯を収束させることは,大量熱電材料の強化のための実行可能な戦略です.
- 達成された高谷退化率とzT値は,熱電気材料の重要な進歩を表しています.
- このアプローチは,効率的な熱から電気への変換のための材料の発見と改善のための一般的な経路を提供します.
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