@article{fd607aed84bd414fb5177bb91b93e4a7,
title = "Multication perovskite 2D/3D interfaces form via progressive dimensional reduction",
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 (MAPbBr3)0.05(FAPbI3)0.95 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.",
author = "Proppe, {Andrew H.} and Andrew Johnston and Sam Teale and Arup Mahata and Rafael Quintero-Bermudez and Jung, {Eui Hyuk} and Luke Grater and Teng Cui and Tobin Filleter and Kim, {Chang Yong} and Kelley, {Shana O.} and {De Angelis}, Filippo and Sargent, {Edward H.}",
note = "Funding Information: This work was supported in part by the US Department of the Navy, Office of Naval Research (grant awards no. N00014-17-1-2524 and N00014-20-1-2572), the Natural Sciences and Engineering Research Council of Canada (NSERC), and the Canada Foundation for Innovation (CFI). A.H.P. was supported by the Canada Graduate Scholarships program from NSERC. The authors thank the Canadian Light Source (CLS) for support in the form of a travel grant. GIWAXS patterns were collected at the BXDS-WLE Beamline at the CLS with the assistance of Dr. Chang-Yong Kim and Dr. Adam Leontowich. The CLS is funded by NSERC, the Canadian Institutes of Health Research, CFI, the Government of Saskatchewan, Western Economic Diversification Canada, and the University of Saskatchewan. S.E.M. images were taken at the Ontario Center for the Characterization of Advanced Materials (OCCAM). ToF-SIMS measurements were performed at Surface Science Western at the University of Western Ontario. Publisher Copyright: {\textcopyright} 2021, The Author(s).",
year = "2021",
month = dec,
day = "1",
doi = "10.1038/s41467-021-23616-9",
language = "English (US)",
volume = "12",
journal = "Nature communications",
issn = "2041-1723",
publisher = "Nature Publishing Group",
number = "1",
}