Blue organic long-persistent luminescence via upconversion from charge-transfer to locally excited singlet state
Long-persistent luminescence (LPL) materials have applications from safety signage to bioimaging; however, existing organic LPL (OLPL) systems do not align with human scotopic vision, which is sensitive to blue light. We present a strategy to blueshift the emissions in binary OLPL systems by upconverting the charge-transfer (CT) to a locally excited (LE) singlet state. Through rigorous steady-state and time-resolved photoluminescence spectroscopy and wavelength-resolved thermoluminescence measurements, we provide the direct experimental evidence for this upconversion in OLPL systems featuring small energy offsets between the lowest-energy CT and LE singlet states. These systems exhibited strong room temperature LPL, particularly when extrinsic electron traps are added. Importantly, the developed OLPL system achieved Class A (ISO 17398) LPL, matching well with human scotopic vision. The findings not only elucidate the role of small energy offsets in modulating LPL but also provide potential avenues for enhancing the efficiency and applicability of OLPL materials.
Authors
- Jin-Ting Ye
- Hayato Ouchi (ORCID: https://orcid.org/0000-0002-8167-6699)
- Rengo Yoshioka (ORCID: https://orcid.org/0000-0002-6380-4140)
- Ryota Kabe (ORCID: https://orcid.org/0000-0002-3647-4262)
- Chihaya Adachi (ORCID: https://orcid.org/0000-0001-6117-9604)
- Shin Shinohara
- Xiankai Chen (ORCID: https://orcid.org/0000-0002-8580-7246)
- Kai Wang (ORCID: https://orcid.org/0000-0002-9860-2282)
- Yuya Tanaka (ORCID: https://orcid.org/0000-0001-7777-0239)
- Hisao Ishii (ORCID: https://orcid.org/0000-0002-7584-2769)
- Yi-Ting Lee (ORCID: https://orcid.org/0000-0001-6860-4896)
- Zesen Lin (ORCID: https://orcid.org/0000-0003-3876-9221)
- Yemineni S. L. V. Narayana (ORCID: https://orcid.org/0000-0001-7024-640X)
- Liliia Moshniaha (ORCID: https://orcid.org/0000-0001-9538-178X)
- Chin‐Yiu Chan (ORCID: https://orcid.org/0000-0001-7721-9244)
- Xun Hai Tang (ORCID: https://orcid.org/0000-0003-3385-1613)
- Kirill Mitrofanov
- Xiaohong Zhang (ORCID: https://orcid.org/0000-0002-6732-2499)
Institutions
- Kyushu University (JP)
- Okinawa Institute of Science and Technology Graduate University (JP)
- Minzu University of China (CN)
- Chiba University (JP)
- Gunma University (JP)
- National University of Singapore (SG)
- Soochow University (CN)
Publication Details
- Journal
- Nature Communications
- Published
- 2025-03-18
- DOI
- https://doi.org/10.1038/s41467-025-58048-2
- Citations
- 18
- Primary Topic
- Luminescence and Fluorescent Materials
- Type
- article
- Field-Weighted Citation Impact
- 9.32
Funders
- Japan Society for the Promotion of Science
- Japan Science and Technology Agency