{
  "abstract": "Day-night solid-state power generation is experimentally demonstrated with thermoelectric generators integrated with a tunable radiative coating, which switches between a selective solar absorber during daytime and a radiative cooler during nighttime by temperature without any external control. The self-adaptive radiative coating is carefully designed with thermochromic VO2 thin film on heavily doped silicon substrate along with a phase-shifting silicon spacer in between, whose physical mechanism is elucidated. The fabricated coating exhibits a high solar absorptivity of 0.90 and a low infrared emissivity of 0.23 during daytime, and a high emissivity of 0.85 at night, resulting in large emissivity change of 0.62 within the atmospheric transparency window upon metal-to-insulator phase transition. From outdoor tests in a high vacuum apparatus, the tunable radiative coating in 35-mm squared size achieves 1.64 W/m2 power generation around noon time from a stack of commercial thermoelectric modules of 15 mm squared, which is 32% more from that with a black absorber. At night, it produces 26 mW/m2 power, outperforming the black emitter by 63%. Even exposed the ambient with convective loss, the 2-inch-round tunable coating generates power of 0.48 W/m2 at noon time, 14% more than the black absorber of the same size. The tunable radiative coating covered thermoelectric modules produces open circuit voltages from 433 mV to -62 mV in vacuum and from 300 mV to -51 mV in ambient through 24-hr continuous outdoor tests.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.36983",
  "author_total": 2,
  "authors": [
    {
      "name": "Ken Araki"
    },
    {
      "name": "Liping Wang"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/6sz7v4425t0n0.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.36983",
  "fulltext_url": null,
  "id": "6sz7v4425t0n0",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.36983",
  "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.mtrl-sci"
    ],
    [
      "openalex",
      "2205|Thermal Radiation and Cooling Technologies"
    ]
  ],
  "openalex": "W7214943286",
  "pdf_url": "https://arxiv.org/pdf/2609.36983",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-29",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/6sz7v4425t0n0.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:25:31Z",
      "native_id": "2609.36983",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.36983"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:cond-mat.mtrl-sci",
      "subfield": "condensed-matter"
    }
  ],
  "title": "24-hr Solid-State Power Generation with Self-Adaptive Tunable Radiative Coatings",
  "title_text": "24-hr Solid-State Power Generation with Self-Adaptive Tunable Radiative Coatings",
  "type": "preprint",
  "updated_at": "2026-10-30T12:25:31Z",
  "url": "https://research.draconitic.com/paper/6sz7v4425t0n0",
  "venue": "arXiv",
  "versions": []
}