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arXiv · 2409.01450

Unveiling the impact of organic cation passivation on structural and optoelectronic properties of two-dimensional perovskites thin films

Israel C. Ribeiro·Pedro Ivo R. Moraes·Albert F. B. Bittencourt·Juarez L. F. Da Silva
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Abstract

Several organic cations have been used to passivate perovskite films; however, selecting the optimal cation remains challenging. In this work, we carried out density functional theory calculations to understand the effects induced by 17 different organic cations on the passivation (P-cations) of thin two-dimensional P2MAn-1PbnI3n+1 perovskites films, where n = 1 and 2. We found that the interactions between different types of P-cations and the inorganic slab affect the length and angles of the bonds within the inorganic framework (PbI6-octahedra). In general, the binding mechanism includes the interactions of organic cations with the inorganic framework, which leads to the accumulation of electron density within the halides, indicative of Bronsted--Lowry acid-base interactions. Oxygenated groups facilitate additional H-bond formation through -OH and -COOH groups, promoting the localization of the electron density between layers and improving the energetic stability of the system. Based on the results and analysis, we found that three P-cations might have higher potential for real-life applications, namely 4-fluorophenylethylammonium (FPEA), phenylethylammonium (PEA) and butylammonium (BtA).

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Israel C. Ribeiro, Pedro Ivo R. Moraes, Albert F. B. Bittencourt, Juarez L. F. Da Silva. 2024-09-02. Unveiling the impact of organic cation passivation on structural and optoelectronic properties of two-dimensional perovskites thin films. https://doi.org/10.1016/j.apsusc.2024.161098

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