固体NMRスペクトロスコーピによるハイブリッドペロブスキート材料におけるカチオンダイナミクスの完全な図
Aditya Mishra1, Michael A Hope1, Michael Grätzel1
1Institut des Sciences et Ingéniere Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015Lausanne, Switzerland.
Journal of the American Chemical Society
|December 29, 2022
まとめ
オーガニックカチオンはペロブスキート太陽電池で急速に回転し,性能に影響します. この研究では,NMRを用いてカチオンダイナミクスを量化し,効率的なペロブスキート太陽電池の設計のためのピコ秒回転時間と洞察を明らかにしました.
科学分野:
- 材料科学
- 固体化学
- 光電子機器
背景:
- ハイブリッドの有機-無機ペロブスキットは,光電子特性により,太陽電池にとって極めて重要です.
- 無機格子内の有機カチオンのダイナミクスは,デバイスの性能に大きな影響を与えます.
- このダイナミクスを理解することは ペロブスキート太陽電池の効率を最適化するための鍵です
研究 の 目的:
- フォーマミディニウムベースのペロブスキートおよび混合カチオンペロブスキートの有機カチオンダイナミクスの定量分析を提供する.
- カチオン回転の活性化エネルギーと相関時間を決定する.
- 太陽電池の設計を改善するために,ペロブスキットの組成と構造とカチオンダイナミクスを相関させる.
主な方法:
- 2Hと14Nの四極性固体MRIリラクソメトリーを用いた.
- マジック・アングル・スピニングを用いて 陽子の回転を分析した.
- 研究されたメチラモニウム (MA+),フォームミジニウム (FA+),グアニジニウム (GUA+) カチオン.
主要な成果:
- すべての調査されたカチオン (MA+,FA+,GUA+) は,室温でピコ秒時間スケールの回転を示す.
- MA+とGUA+は,それぞれ高速と遅いローテーションコンポーネントを示しています.
- カチオンのダイナミクスは,無機格子対称性によって影響を受けますが,カチオンの置換レベルによって影響を受けません. FA + 回転は相変化を超えて不変です.
結論:
- カチオンダイナミクスの正確な特徴は,ペロブスキットの光電子特性におけるその役割のより深い理解を提供します.
- この洞察は より効率的なペロブスキート太陽電池の設計に役立つでしょう
- パラ磁性欠陥への拡散による特定のペロブスキート組成物におけるMA+の異常な緩和メカニズムを特定した.
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