ブロームの組み込みは,鉛ハリドペロフスキートの相変化と熱安定性に影響する
Diana K LaFollette1, Juanita Hidalgo1, Omar Allam2
1School of Materials Science and Engineering, Georgia Institute of Technology, North Ave NW, Atlanta, Georgia 30332, United States.
Journal of the American Chemical Society
|June 27, 2024
まとめ
太陽電池用のセシウム,ホルマミドニウム,鉛,ヨウ素ペロブスキートにブロミンを加えると熱安定性が低下する. ブロームの組み込みは,ヨウ素のみの材料とは異なり,鉛ヨウ化物への不可逆的な相変換につながります.
科学分野:
- 材料科学
- 固体化学
- 太陽光発電
背景:
- 混合カチオンと混合ハリド鉛ハリドペロブスキットは太陽電池の用途に有望です.
- 高性能ペロブスキート組成には,しばしばセシウム,ホルマミドニウム,鉛,ヨウ素,およびブロミンが含まれます.
- ヨウ素に富んだペロブスキットの熱安定性に対するブロームの組み込みの影響は,まだ十分に研究されていない.
研究 の 目的:
- ペロフスキットにおけるヨウ素をブロムに置き換えることで,相変換のダイナミクスと熱安定性に与える影響を調査する.
- 熱力学的な安定性と相変化経路にブロンがどのように影響するかを理解する.
主な方法:
- 構造的特徴
- カソドルミネッセンスマッピング
- X線光電子スペクトル
- 最初の原則の計算
主要な成果:
- ブロームの組み込みは,ペロブスキート膜の熱力学的相安定性を低下させる.
- ブロームの組み込みは,高温で相変化の産物を移動させます.
- ブロムによる空白形成は,鉛ヨウ酸化物 (PbI_{2}$) に不可逆的な変容をもたらし,ヨウ素のみの材料は,4H-FAPbI_{3}$のような六角形のポリタイプに変容する.
結論:
- ブロム添加は,ペロブスキットの熱力学的相安定性に負の影響を及ぼします.
- 段階変換と二次相形成におけるブロムの役割を理解することは,安定した混合ハリドペロブスキート太陽電池の設計に不可欠です.
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