Interlayer Mismatch and Solvated Intermediates Control Spacer Mixing in 2D Perovskites
- 1Department of Chemistry
- 2University of Utah
- 3Utah Nanofab Electron Microscopy and Surface Analysis Laboratory
Abstract
Organic spacer mixing is a versatile strategy for tuning the structure and properties of two-dimensional layered halide perovskites (2DLHPs), yet the factors that govern the resulting mixing configuration remain poorly understood. Here we investigate mixtures of alkyl monoammonium Ruddlesden–Popper (RP) and alkyl diammonium Dion–Jacobson (DJ) 2DLHPs and identify three structural outcomes: alloying, phase separation, and superlattice formation. Across twenty spacer combinations, the interlayer-spacing mismatch between the parent perovskites largely determines the outcome, with small mismatch favoring alloys and large mismatch favoring phase separation. A superlattice phase with a period exceeding either parent, consistent with alternating RP and DJ layers, forms only at large mismatch and only for blends containing 1,4-butanediammonium (DC4). In situ absorption spectroscopy and single-crystal structure determination reveal that superlattice formation proceeds through a dimethylformamide (DMF)-containing intermediate in which DC4 and n-pentylammonium (C5) occupy distinct bridging and intercalated crystallographic sites, producing an ordered precursor that converts to the superlattice upon annealing. Structural mismatch and intermediate-phase chemistry together govern alloying, phase separation, and superlattice formation in mixed-spacer 2DLHPs.
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BibTeX
@misc{wei2026interlayer,
title = {{Interlayer Mismatch and Solvated Intermediates Control Spacer Mixing in 2D Perovskites}},
author = {Yunhao Wei and Perry W. Martin and Rae A. Hunter and Bobby G. Duersch and Ryan T. VanderLinden and Connor G. Bischak},
howpublished = {ChemRxiv},
year = {2026},
month = sep,
doi = {10.26434/chemrxiv.15009404/v1},
url = {https://chemrxiv.org/doi/full/10.26434/chemrxiv.15009404/v1},
note = {CC BY},
}
RIS
TY - UNPB
TI - Interlayer Mismatch and Solvated Intermediates Control Spacer Mixing in 2D Perovskites
AU - Yunhao Wei
AU - Perry W. Martin
AU - Rae A. Hunter
AU - Bobby G. Duersch
AU - Ryan T. VanderLinden
AU - Connor G. Bischak
PY - 2026
DA - 2026/09/23
PB - ChemRxiv
DO - 10.26434/chemrxiv.15009404/v1
UR - https://chemrxiv.org/doi/full/10.26434/chemrxiv.15009404/v1
AB - Organic spacer mixing is a versatile strategy for tuning the structure and properties of two-dimensional layered halide perovskites (2DLHPs), yet the factors that govern the resulting mixing configuration remain poorly understood. Here we investigate mixtures of alkyl monoammonium Ruddlesden–Popper (RP) and alkyl diammonium Dion–Jacobson (DJ) 2DLHPs and identify three structural outcomes: alloying, phase separation, and superlattice formation. Across twenty spacer combinations, the interlayer-spacing mismatch between the parent perovskites largely determines the outcome, with small mismatch favoring alloys and large mismatch favoring phase separation. A superlattice phase with a period exceeding either parent, consistent with alternating RP and DJ layers, forms only at large mismatch and only for blends containing 1,4-butanediammonium (DC4). In situ absorption spectroscopy and single-crystal structure determination reveal that superlattice formation proceeds through a dimethylformamide (DMF)-containing intermediate in which DC4 and n-pentylammonium (C5) occupy distinct bridging and intercalated crystallographic sites, producing an ordered precursor that converts to the superlattice upon annealing. Structural mismatch and intermediate-phase chemistry together govern alloying, phase separation, and superlattice formation in mixed-spacer 2DLHPs.
ER -