{
  "abstract": "Semiconducting Mo$_x$W$_{1-x}$Se$_2$ alloys provide a versatile platform for tailoring the optical properties of two-dimensional materials through both composition and layer thickness. Here, we systematically investigate mechanically exfoliated Mo$_{0.58}$W$_{0.42}$Se$_2$ flakes ranging from monolayer (1L) to nine layers by combining Raman scattering (RS), photoluminescence (PL), reflectance contrast (RC) spectroscopy, and first-principles phonon calculations. Thirteen RS peaks are identified, including the low-frequency interlayer shear mode, whose thickness dependence is well described by a linear-chain model, yielding an interlayer force constant of $K_s=(2.996\\pm0.015)\\times10^{19}$ N m$^{-3}$. PL measurements reveal a crossover from the direct-bandgap 1L to indirect-bandgap multilayers. The thickness evolution of the indirect optical transition is quantitatively reproduced using a quantum-confinement model, yielding an out-of-plane reduced effective mass of $μ_\\perp=0.75 m_0$. RC spectroscopy reveals four excitonic resonances. While the A and B excitons associated with the $K^\\pm$ valleys remain nearly independent of layer thickness, the higher-energy C and D resonances originating from the band-nesting regions exhibit pronounced redshifts, reflecting substantial thickness-induced modifications of the electronic band structure. These results establish comprehensive spectroscopic fingerprints of flake thickness, interlayer coupling, and electronic structure in Mo$_x$W$_{1-x}$Se$_2$ alloys and provide a reliable, non-destructive framework for their optical characterization.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.18572",
  "author_total": 10,
  "authors": [
    {
      "name": "Szymon Socha"
    },
    {
      "name": "Tomasz Wozniak"
    },
    {
      "name": "Elena Blundo"
    },
    {
      "name": "Malgorzata Brzoska"
    },
    {
      "name": "Grzegorz Krasucki"
    },
    {
      "name": "Piotr Wrobel"
    },
    {
      "name": "Antonio Polimeni"
    },
    {
      "name": "Adam Babinski"
    },
    {
      "name": "Maciej R. Molas"
    },
    {
      "name": "Katarzyna Olkowska-Pucko"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/adrgzb5q3ajp8.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.18572",
  "fulltext_url": null,
  "id": "adrgzb5q3ajp8",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.18572",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "http://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "cond-mat.mes-hall"
    ],
    [
      "arxiv",
      "cond-mat.mtrl-sci"
    ],
    [
      "openalex",
      "2505|2D Materials and Applications"
    ]
  ],
  "openalex": "W7213502336",
  "pdf_url": "https://arxiv.org/pdf/2609.18572",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-16",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/adrgzb5q3ajp8.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:22:01Z",
      "native_id": "2609.18572",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.18572"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:cond-mat.mes-hall",
      "subfield": "condensed-matter"
    }
  ],
  "title": "Layer-Dependent Vibrational and Optical Properties of $\\mathrm{Mo}{0.58}\\mathrm{W}{0.42}\\mathrm{Se}_2$ Alloy",
  "title_text": "Layer-Dependent Vibrational and Optical Properties of Mo0.58W0.42Se_2 Alloy",
  "type": "preprint",
  "updated_at": "2026-10-30T12:22:01Z",
  "url": "https://research.draconitic.com/paper/adrgzb5q3ajp8",
  "venue": "arXiv",
  "versions": []
}