Probing Local Coordination and Halide Miscibility in Single-, Double-, and Triple-Halide Perovskites Using EXAFS
Mulgund, Sonia S. ; Hung, Esther Y.H. LU ; Bostwick, Leslie ; Galbraith, Ashley ; Romberg, Owen M. ; Just, Justus LU
and Belisle, Rebecca A.
(2026)
In Journal of Physical Chemistry C
130(32).
p.11446-11457
- Abstract
Lead-halide perovskites are a promising material platform as semiconductors in next-generation solar cells because of their solution processability, defect tolerance, and tunable optoelectronic properties. Mixed iodide–bromide perovskite compositions are attractive as wide-bandgap absorbers but suffer from significant operational instabilities. Incorporation of chloride to form triple-halide perovskites has been shown to improve both stability and performance; however, the extent of halide miscibility and chloride incorporation remains poorly understood. While bulk metrics such as diffraction-derived lattice parameters and optical bandgaps can confirm single-phase behavior, they do not establish homogeneous mixing on the halide site.... (More)
Lead-halide perovskites are a promising material platform as semiconductors in next-generation solar cells because of their solution processability, defect tolerance, and tunable optoelectronic properties. Mixed iodide–bromide perovskite compositions are attractive as wide-bandgap absorbers but suffer from significant operational instabilities. Incorporation of chloride to form triple-halide perovskites has been shown to improve both stability and performance; however, the extent of halide miscibility and chloride incorporation remains poorly understood. While bulk metrics such as diffraction-derived lattice parameters and optical bandgaps can confirm single-phase behavior, they do not establish homogeneous mixing on the halide site. Here, we use cryogenic X-ray absorption spectroscopy (XAS) to directly probe local lead-halide coordination across single-, double-, and triple-halide perovskite compositions. We show the formation of a single-phase triple-halide perovskite whose miscibility is mediated by bromide content. We identify signatures of halide mixing from the Pb L3-edge EXAFS of mixed double- and triple-halide perovskites using both quantitative fits and Cauchy wavelet transforms. Finally, using wavelet transforms of the Br K-edge EXAFS, we demonstrate halide intermixing on the single PbX6 octahedron level, exploiting forward-scattering amplified third-shell halide–bromide interactions. These results are a step forward in the understanding of local structure that is required to fully describe and optimize halide incorporation for novel perovskite compositions.
(Less)
- author
- Mulgund, Sonia S.
; Hung, Esther Y.H.
LU
; Bostwick, Leslie
; Galbraith, Ashley
; Romberg, Owen M.
; Just, Justus
LU
and Belisle, Rebecca A.
- organization
- publishing date
- 2026-08-13
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Journal of Physical Chemistry C
- volume
- 130
- issue
- 32
- pages
- 12 pages
- publisher
- The American Chemical Society (ACS)
- external identifiers
-
- pmid:42609771
- scopus:105047329620
- ISSN
- 1932-7447
- DOI
- 10.1021/acs.jpcc.6c03620
- language
- English
- LU publication?
- yes
- id
- 7dda9632-03ff-4a96-ba05-907e5dd03842
- date added to LUP
- 2026-09-29 14:56:09
- date last changed
- 2026-09-30 03:00:06
@article{7dda9632-03ff-4a96-ba05-907e5dd03842,
abstract = {{<p>Lead-halide perovskites are a promising material platform as semiconductors in next-generation solar cells because of their solution processability, defect tolerance, and tunable optoelectronic properties. Mixed iodide–bromide perovskite compositions are attractive as wide-bandgap absorbers but suffer from significant operational instabilities. Incorporation of chloride to form triple-halide perovskites has been shown to improve both stability and performance; however, the extent of halide miscibility and chloride incorporation remains poorly understood. While bulk metrics such as diffraction-derived lattice parameters and optical bandgaps can confirm single-phase behavior, they do not establish homogeneous mixing on the halide site. Here, we use cryogenic X-ray absorption spectroscopy (XAS) to directly probe local lead-halide coordination across single-, double-, and triple-halide perovskite compositions. We show the formation of a single-phase triple-halide perovskite whose miscibility is mediated by bromide content. We identify signatures of halide mixing from the Pb L<sub>3</sub>-edge EXAFS of mixed double- and triple-halide perovskites using both quantitative fits and Cauchy wavelet transforms. Finally, using wavelet transforms of the Br K-edge EXAFS, we demonstrate halide intermixing on the single PbX<sub>6</sub> octahedron level, exploiting forward-scattering amplified third-shell halide–bromide interactions. These results are a step forward in the understanding of local structure that is required to fully describe and optimize halide incorporation for novel perovskite compositions.</p>}},
author = {{Mulgund, Sonia S. and Hung, Esther Y.H. and Bostwick, Leslie and Galbraith, Ashley and Romberg, Owen M. and Just, Justus and Belisle, Rebecca A.}},
issn = {{1932-7447}},
language = {{eng}},
month = {{08}},
number = {{32}},
pages = {{11446--11457}},
publisher = {{The American Chemical Society (ACS)}},
series = {{Journal of Physical Chemistry C}},
title = {{Probing Local Coordination and Halide Miscibility in Single-, Double-, and Triple-Halide Perovskites Using EXAFS}},
url = {{http://dx.doi.org/10.1021/acs.jpcc.6c03620}},
doi = {{10.1021/acs.jpcc.6c03620}},
volume = {{130}},
year = {{2026}},
}