高性能 n型 PbSe-Cu2Se 導電帯工学とフォノン軟化による熱電学
Chongjian Zhou1, Yuan Yu2, Yong Kyu Lee1
1Center for Nanoparticle Research , Institute for Basic Science (IBS) , Seoul 08826 , Republic of Korea.
Journal of the American Chemical Society
|October 23, 2018
まとめ
テルリウム無鉛セレニド (PbSe) に銅セレニド (Cu2Se) を添加すると,熱電性能の記録を達成します. この材料は,中温の発電用途に有望で費用対効果の高い代替手段を提供します.
科学分野:
- 材料科学
- 固体物理学
- エネルギー変換
背景:
- テルリウム無鉛セレニド (PbSe) は,熱電発電のための鉛テルリド (PbTe) の費用対効果の高い代替品として検討されています.
- 効率的な熱電性材料の開発は,廃棄熱の回収と持続可能なエネルギーソリューションに不可欠です.
研究 の 目的:
- ブロムと銅のセレニドを添加した鉛セレニド (PbSe0.998Br0.002-2%Cu2Se) の熱電性について調査する.
- 中間温度のアプリケーションの高値値 (ZT) を達成する.
主な方法:
- PbSe0.998Br0.002-2%Cu2Seの合成と特徴づけ
- 電気伝送特性 (シーベック係数,電気伝導性,パワーファクター) の測定
- 熱伝導特性 (熱伝導性) の測定
- 基礎となるメカニズムを理解するために
主要な成果:
- 723 KのピークZTは1.8で,n型およびp型PbSe材料の平均ZTは1.1 (300823 K) である.
- Cu2Seドーピングは,伝導帯のエッジを平らにし,有効質量を増加させることでシーベック係数を高めました.
- 格子熱伝導性は773 Kで ~0.4 W m−1 K−1 に大幅に低下し,無形限界に近づいています.
- 幅広い温度範囲で~2126μWcm−2 K−2の超高出力因子を達成した.
結論:
- PbSe0.998Br0.002-2%Cu2Seは,n型PbTe材料と競合する優れた熱電気性能を示しています.
- Cu2Seドーピングは,電荷輸送を効果的に強化し,n型PbSeの熱伝導性を抑制する.
- この研究は,PbSeの電子帯構造を操作することによって,熱電特性最適化のための成功した戦略を提示します.
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