{
  "abstract": "Lead-free halide double perovskites are promising materials for light-emitting and photovoltaic applications. However, compositional tuning of their structural and optoelectronic properties has largely focused on B-site and halide alloying. In this work, we show that Cs + on the perovskite A-site of Cs 2 AgInCl 6 can be partly substituted with Rb + using simple apolar liquid-assisted mechanochemistry. By comparing Rb + with Na + substitution we show that ion size drives the site-selectivity of alkali ion substitution into double perovskites, with Na + preferentially occupying the perovskite B-site. By combining multinuclear solid-state nuclear magnetic resonance spectroscopy with X-ray diffraction, we show that Rb+ not only enters the double-perovskite site-selectively but also induces local symmetry breaking of the cubic structure, comparable to the effect of B-site Na + /Ag + alloying, with important implications for symmetry-forbidden photoluminescence emissivity. This work extends the tuneable compositional range of lead-free double perovskites to include A-site mixing while also establishing the site-selectivity of alkali ion speciation into the double perovskite structure.",
  "abstract_shown": true,
  "affiliations": [
    "School of Chemistry",
    "University of Birmingham",
    "Department of Physics and Astronomy",
    "Chalmers University of Technology",
    "Department of Chemical Engineering",
    "University College London",
    "Department of Solution-Processing of Hybrid Materials and Devices Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Kekuléstraße 5, Berlin, Germany, 12489"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 8,
  "authors": [
    {
      "affs": [
        0,
        1
      ],
      "name": "Kaja Glazer"
    },
    {
      "affs": [
        2,
        3
      ],
      "name": "Julia Wiktor"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Luis Simbari"
    },
    {
      "affs": [
        4,
        5
      ],
      "name": "Mo Al Al Maoued"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Anya Fairhurst"
    },
    {
      "affs": [
        4,
        5
      ],
      "name": "Amita Ummadishingu"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Dominik J. Kubicki"
    },
    {
      "affs": [
        0,
        1,
        6
      ],
      "name": "Benjamin M. Gallant",
      "orcid": "0000-0001-7413-291X"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/32ak3pmpxpq49.bib",
  "cited_by": 0,
  "doi": "10.26434/chemrxiv.15008057/v1",
  "fulltext_url": null,
  "id": "32ak3pmpxpq49",
  "issns": [],
  "landing_url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15008057/v1",
  "language": null,
  "licence": "CC-BY",
  "licence_label": "CC BY",
  "licence_source": "journal",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "2208|Perovskite Materials and Applications"
    ]
  ],
  "openalex": "W7204798298",
  "pdf_url": "https://chemrxiv.org/doi/pdf/10.26434/chemrxiv.15008057/v1",
  "pmcid": null,
  "pmid": null,
  "published": "2026-08-30",
  "publisher": "American Chemical Society (ACS)",
  "ris": "https://research.draconitic.com/paper/32ak3pmpxpq49.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:17Z",
      "native_id": "10.26434/chemrxiv.15008057",
      "source": "chemrxiv",
      "url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15008057/v3"
    }
  ],
  "subjects": [
    {
      "field": "chemistry",
      "origin": "source:chemrxiv",
      "subfield": "general"
    }
  ],
  "title": "Site-selective alkali ion alloying in double perovskites via liquid-assisted mechanosynthesis revealed by solid-state NMR",
  "title_text": "Site-selective alkali ion alloying in double perovskites via liquid-assisted mechanosynthesis revealed by solid-state NMR",
  "type": "preprint",
  "updated_at": "2026-10-30T12:17:24Z",
  "url": "https://research.draconitic.com/paper/32ak3pmpxpq49",
  "venue": "ChemRxiv",
  "versions": []
}