About this Abstract |
| Meeting |
2026 TMS Annual Meeting & Exhibition
|
| Symposium
|
2D Materials – Preparation, Properties, Modeling & Applications
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| Presentation Title |
Ab Initio Molecular Dynamics Investigation of Moisture-Induced Surface Degradation in FAPbI₃ Perovskite: Role of Water Adsorption and Surface Termination |
| Author(s) |
Md Atikur Rahman, Zonghua Peng, Masud H Chowdhury |
| On-Site Speaker (Planned) |
Md Atikur Rahman |
| Abstract Scope |
Formamidinium lead iodide (FAPbI₃) perovskites hold great promise in next-generation optoelectronic devices due to their superior optical and electronic properties. However, their long-term environmental stability—particularly against moisture—remains a critical challenge. In this study, we employed ab initio molecular dynamics (AIMD) simulations using the CP2K package to investigate the interaction between a FAPbI₃ perovskite slab and water molecules. We explored the structural evolution of the water/perovskite interface under thermal conditions to understand the initial stages of degradation. FAPbI3 with two different termination systems has been considered for this study to assess their effect. The simulations reveal that water molecules, which initially reside above the surface, gradually adsorb toward the lattice and form coordination bonds with undercoordinated surface Pb²⁺ ions in the PbI2-terminated system. This Pb–O bonding indicates the onset of chemical degradation, leading to distortion of the PbI₆ octahedral network. AIMD results show that water forms hydrogen bonds with FA⁺ cations on the FAI-terminated FAPbI₃ surface, offering partial protection but still allowing gradual moisture-driven degradation. Water exposure widens the bandgap of FAPbI₃, flattens its bands, and alters k-point symmetry, thereby reducing charge transport efficiency compared to pure FAPbI₃.Our findings provide a fundamental understanding of moisture-induced degradation mechanisms in FAPbI₃ and highlight the importance of surface engineering to enhance perovskite device stability under humid conditions. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Modeling and Simulation, Phase Transformations, Thin Films and Interfaces |