{
  "abstract": "The discovery of ferroelectric ScAlN sparked a search for new polar wurtzite alloys; however, incorporating transition metals remains a formidable challenge. Here, we demonstrate the synthesis of wurtzite‐phase NbAlN, a polar transition‐metal nitride alloy that is highly compatible with GaN‐based heterostructures. Despite the strong metallic character of elemental Nb, we achieved coherent epitaxial NbAlN films that preserve the wurtzite crystal structure and metal polarity of the underlying GaN, as directly visualized by annular bright‐field scanning transmission electron microscopy. Nb incorporation induces a monotonic lattice expansion and produces coherent Nb‐enriched nanoscale regions that are accommodated within the continuous wurtzite framework. Functionally, NbAlN barriers induce a substantial enhancement in the two‐dimensional electron gas density at the AlN/GaN heterointerface, consistent with polarization‐related carrier modulation by the metal‐polar NbAlN barrier. This study demonstrates that d‐electron transition metals can be integrated into polar nitride systems without compromising their functional asymmetry, making NbAlN a promising building block for polar nitride heterostructures and carrier‐density‐engineered GaN electronics.",
  "abstract_shown": true,
  "affiliations": [
    "Department of Materials Science and Technology Tokyo University of Science Tokyo Japan",
    "Department of Electrical Engineering and Information Systems The University of Tokyo Tokyo Japan",
    "Innovation Center for Semiconductor and Digital Future Mie University Mie Japan",
    "Graduate School of Engineering Mie University Mie Japan",
    "Institute of Engineering Innovation School of Engineering The University of Tokyo Tokyo Japan"
  ],
  "article_type": "research article",
  "arxiv": null,
  "author_total": 13,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Atsushi Kobayashi",
      "orcid": "0000-0001-5795-6490"
    },
    {
      "affs": [
        0
      ],
      "name": "Souta Kurogi"
    },
    {
      "affs": [
        0
      ],
      "name": "Tomoya Okuda",
      "orcid": "0009-0009-2975-706X"
    },
    {
      "affs": [
        0
      ],
      "name": "Riku Kikuchi"
    },
    {
      "affs": [
        1
      ],
      "name": "Yusuke Wakamoto",
      "orcid": "0009-0007-7340-0899"
    },
    {
      "affs": [
        1
      ],
      "name": "Kouei Kubota"
    },
    {
      "affs": [
        1
      ],
      "name": "Hikaru Sasaki"
    },
    {
      "affs": [
        0
      ],
      "name": "Kazuhisa Ikeda",
      "orcid": "0009-0008-6883-9837"
    },
    {
      "affs": [
        2,
        3
      ],
      "name": "Kanako Shojiki",
      "orcid": "0000-0003-0781-7016"
    },
    {
      "affs": [
        2,
        3
      ],
      "name": "Takahiro Kawamura",
      "orcid": "0000-0002-6024-0634"
    },
    {
      "affs": [
        2,
        3
      ],
      "name": "Toru Akiyama",
      "orcid": "0000-0002-2800-2011"
    },
    {
      "affs": [
        4
      ],
      "name": "Takehito Seki",
      "orcid": "0000-0001-5437-6351"
    },
    {
      "affs": [
        1
      ],
      "name": "Takuya Maeda",
      "orcid": "0000-0002-2736-5611"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/fh1a9bqzv6xmf.bib",
  "cited_by": 0,
  "doi": "10.1002/adma.74756",
  "fulltext_url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC13712217/",
  "id": "fh1a9bqzv6xmf",
  "issns": [
    "0935-9648",
    "1521-4095"
  ],
  "landing_url": "https://doi.org/10.1002/adma.74756",
  "language": "en",
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "heading",
      "Research Article"
    ],
    [
      "openalex",
      "3104|GaN-based semiconductor devices and materials"
    ]
  ],
  "openalex": "W7207761120",
  "pdf_url": "https://onlinelibrary.wiley.com/doi/pdfdirect/10.1002/adma.74756",
  "pmcid": "PMC13712217",
  "pmid": "42690613",
  "published": "2026-09-03",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/fh1a9bqzv6xmf.ris",
  "sources": [
    {
      "first_seen": "2026-10-31T12:22:50Z",
      "native_id": "PMC13712217",
      "source": "pmc",
      "url": "https://doi.org/10.1002/adma.74756"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "openalex:3104|GaN-based semiconductor devices and materials",
      "subfield": "condensed-matter"
    }
  ],
  "title": "Polar Wurtzite NbAlN: A Transition‐Metal Nitride Alloy for Polarization‐Engineered GaN Heterostructures",
  "title_text": "Polar Wurtzite NbAlN: A Transition‐Metal Nitride Alloy for Polarization‐Engineered GaN Heterostructures",
  "type": "peer-reviewed",
  "updated_at": "2026-10-31T12:22:50Z",
  "url": "https://research.draconitic.com/paper/fh1a9bqzv6xmf",
  "venue": "Advanced Materials (Deerfield Beach, Fla.)",
  "versions": []
}