2023-12-19 ジョージア工科大学
◆これにより、既存のシリコンベース太陽電池と同等の効率を持つこの素材の主要な制約の一部が克服され、太陽エネルギーの生産やLED、フォトトランジスタなどの半導体製造において革新的な進展が期待されます。
＜関連情報＞
- https://research.gatech.edu/researchers-find-they-can-stop-degradation-promising-solar-cell-materials
- https://pubs.acs.org/doi/10.1021/jacs.3c05657
水と酸素の相乗作用がホルムアミジニウム系ハロゲン化物ペロブスカイトの劣化を引き起こす Synergistic Role of Water and Oxygen Leads to Degradation in Formamidinium-Based Halide Perovskites
Juanita Hidalgo, Waldemar Kaiser, Yu An, Ruipeng Li, Zion Oh, Andrés-Felipe Castro-Méndez, Diana K. LaFollette, Sanggyun Kim, Barry Lai, Joachim Breternitz, Susan Schorr, Carlo A. R. Perini, Edoardo Mosconi, Filippo De Angelis, and Juan-Pablo Correa-Baena
Journal of the American Chemical Society published:November 2, 2023
DOI:https://doi.org/10.1021/jacs.3c05657
Abstract
Mixed-cation metal halide perovskites have shown remarkable progress in photovoltaic applications with high power conversion efficiencies. However, to achieve large-scale deployment of this technology, efficiencies must be complemented by long-term durability. The latter is limited by external factors, such as exposure to humidity and air, which lead to the rapid degradation of the perovskite materials and devices. In this work, we study the mechanisms causing Cs and formamidinium (FA)-based halide perovskite phase transformations and stabilization during moisture and air exposure. We use in situ X-ray scattering, X-ray photoelectron spectroscopy, and first-principles calculations to study these chemical interactions and their effects on structure. We unravel a surface reaction pathway involving the dissolution of FAI by water and iodide oxidation by oxygen, driving the Cs/FA ratio into thermodynamically unstable regions, leading to undesirable phase transformations. This work demonstrates the interplay of bulk phase transformations with surface chemical reactions, providing a detailed understanding of the degradation mechanism and strategies for designing durable and efficient perovskite materials.
