@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}},
}