{
  "abstract": "The continuing demand for sharper and brighter displays is driving the development of efficient blue organic light-emitting diodes (OLEDs). However, achieving high maximum external quantum efficiency (EQE max ) and low efficiency roll-off is still a major challenge for blue-emitting devices. Herein, we report highly efficient blue multi-resonant thermally activated delayed fluorescent (MR-TADF) OLEDs showing EQE max of 32.5% and relatively moderate efficiency roll-off (EQE: 26.3% at 100 cd m -2 and 14.6% at 1000 cd m -2 ). Several host:emitter combinations were explored to correlate the nature of the emissive layer formulation to the 2 differences in device efficiencies. Here, the photophysical measurements did not adequately explain the differences in device performance; however, direct measurement of exciton dynamics in operating OLEDs and single-carrier devices revealed that charge accumulation at the interface between the transport layer and host resulted in increased exciton-polaron annihilation and the loss of efficiency. This highlights the importance of measurements on operating devices, as the differences in efficiency between devices could not be explained by conventional photophysics alone.",
  "abstract_shown": true,
  "affiliations": [
    "SUPA School of Physics and Astronomy",
    "University of St Andrews",
    "Organic Semiconductor Centre, EaStCHEM School of Chemistry"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 7,
  "authors": [
    {
      "affs": [
        0,
        1
      ],
      "name": "Hassan Hafeez"
    },
    {
      "affs": [
        2,
        1
      ],
      "name": "Sen Wu"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Liam King"
    },
    {
      "affs": [
        2,
        1
      ],
      "name": "Quan Qi"
    },
    {
      "affs": [
        2,
        1
      ],
      "name": "David B. Cordes"
    },
    {
      "affs": [
        2,
        1
      ],
      "name": "Eli Zysman-Colman",
      "orcid": "0000-0001-7183-6022"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Ifor D. W. Samuel"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/f7a7r82d0trkm.bib",
  "cited_by": 0,
  "doi": "10.26434/chemrxiv.15009008/v1",
  "fulltext_url": null,
  "id": "f7a7r82d0trkm",
  "issns": [],
  "landing_url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15009008/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|Organic Light-Emitting Diodes Research"
    ]
  ],
  "openalex": "W7213504931",
  "pdf_url": "https://chemrxiv.org/doi/pdf/10.26434/chemrxiv.15009008/v1",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-17",
  "publisher": "American Chemical Society (ACS)",
  "ris": "https://research.draconitic.com/paper/f7a7r82d0trkm.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:19Z",
      "native_id": "10.26434/chemrxiv.15009008",
      "source": "chemrxiv",
      "url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15009008/v1"
    }
  ],
  "subjects": [
    {
      "field": "chemistry",
      "origin": "source:chemrxiv",
      "subfield": "general"
    }
  ],
  "title": "Development of Efficient Blue OLEDs: A Systematic Investigation of the Effect of the Nature of the Host on Exciton Dynamics in Operating TADF Devices",
  "title_text": "Development of Efficient Blue OLEDs: A Systematic Investigation of the Effect of the Nature of the Host on Exciton Dynamics in Operating TADF Devices",
  "type": "preprint",
  "updated_at": "2026-10-30T12:17:19Z",
  "url": "https://research.draconitic.com/paper/f7a7r82d0trkm",
  "venue": "ChemRxiv",
  "versions": []
}