Multication perovskite 2D/3D interfaces form via progressive dimensional reduction.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 34108463.
- Also identified by DOI 10.1038/s41467-021-23616-9 and PMC identifier 8190276.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Many of the best-performing perovskite photovoltaic devices make use of 2D/3D interfaces, which improve efficiency and stability - but it remains unclear how the conversion of 3D-to-2D perovskite occurs and how these interfaces are assembled. Here, we use in situ Grazing-Incidence Wide-Angle X-Ray Scattering to resolve 2D/3D interface formation during spin-coating. We observe progressive dimensional reduction from 3D to n = 3 → 2 → 1 when we expose (MAPbBr<sub>3</sub>)<sub>0.05</sub>(FAPbI<sub>3</sub>)<sub>0.95</sub> perovskites to vinylbenzylammonium ligand cations. Density functional theory simulations suggest ligands incorporate sequentially into the 3D lattice, driven by phenyl ring stacking, progressively bisecting the 3D perovskite into lower-dimensional fragments to form stable interfaces. Slowing the 2D/3D transformation with higher concentrations of antisolvent yields thinner 2D layers formed conformally onto 3D grains, improving carrier extraction and device efficiency (20% 3D-only, 22% 2D/3D). Controlling this progressive dimensional reduction has potential to further improve the performance of 2D/3D perovskite photovoltaics.