Microscopic (dis)order and dynamics of cations in mixed FA/MA lead halide perovskites
| Autor: | Ralf Moos, Gilles A. de Wijs, Menno Bokdam, Arno P. M. Kentgens, Nico Leupold, Paul Tinnemans, Fabian Panzer, Helen Grüninger |
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| Přispěvatelé: | Computational Materials Science, MESA+ Institute |
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Materials science
UT-Hybrid-D Halide 02 engineering and technology Solid State Chemistry 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Solid State NMR Article 0104 chemical sciences Surfaces Coatings and Films Electronic Optical and Magnetic Materials General Energy Chemical physics Physical and Theoretical Chemistry 0210 nano-technology Theoretical Chemistry Perovskite (structure) |
| Zdroj: | Journal of Physical Chemistry C, 125, 1742-1753 Journal of Physical Chemistry C, 125, 3, pp. 1742-1753 Journal of physical chemistry C, 125, 1742-1753. American Chemical Society The Journal of Physical Chemistry. C, Nanomaterials and Interfaces |
| ISSN: | 1932-7447 |
| DOI: | 10.1021/acs.jpcc.0c10042 |
| Popis: | Recent developments in the field of high efficiency perovskite solar cells are based on stabilization of the perovskite crystal structure of FAPbI3 while preserving its excellent optoelectronic properties. Compositional engineering of, for example, MA or Br mixed into FAPbI3 results in the desired effects, but detailed knowledge of local structural features, such as local (dis)order or cation interactions of formamidinium (FA) and methylammonium (MA), is still limited. This knowledge is, however, crucial for their further development. Here, we shed light on the microscopic distribution of MA and FA in mixed perovskites MA1–xFAxPbI3 and MA0.15FA0.85PbI2.55Br0.45 by combining high-resolution double-quantum 1H solid-state nuclear magnetic resonance (NMR) spectroscopy with state-of-the-art near-first-principles accuracy molecular dynamics (MD) simulations using machine-learning force-fields (MLFFs). We show that on a small local scale, partial MA and FA clustering takes place over the whole MA/FA compositional range. A reasonable driving force for the clustering might be an increase of the dynamical freedom of FA cations in FA-rich regions. While MA0.15FA0.85PbI2.55Br0.45 displays similar MA and FA ordering as the MA1–xFAxPbI3 systems, the average cation–cation interaction strength increased significantly in this double mixed material, indicating a restriction of the space accessible to the cations or their partial immobilization upon Br– incorporation. Our results shed light on the heterogeneities in cation composition of mixed halide perovskites, helping to exploit their full optoelectronic potential. |
| Databáze: | OpenAIRE |
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