Improvement of photon upconversion utilizing characteristics of localized surface plasmon resonance

2022 Fiscal Year Final Research Report

• Project/Area Number: 20H02850
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 36020:Energy-related chemistry
• Research Institution: Nihon University
• Principal Investigator: SUGAWA Kosuke 日本大学, 理工学部, 教授 (40580204)
• Co-Investigator(Kenkyū-buntansha): 加藤 隆二 日本大学, 工学部, 教授 (60204509) ; 田原 弘宣 長崎大学, 工学研究科, 助教 (80631407)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 表面プラズモン共鳴 / アップコンバージョン / 三重項対消滅 / 近接場効果 / 遠隔場効果 / 局所熱

Outline of Final Research Achievements

Plasmonic nanomaterials, which generate local heat through localized surface plasmon (LSP) resonance upon near-infrared light excitation, were combined with polymer host-based thin films for triplet-triplet annihilation-based upconversion (TTA-UC). This hybridization resulted in a significant improvement in the energy transfer efficiency between the triplet-excited sensitizer and emitter, leading to enhanced upconversion (UC) emission. Also, we achieved enhancement in UC emission by leveraging strong local magnetic fields using metal/insulator/metal structures composed of silver films, TTA-UC films, and silver nanocubes. This approach significantly improved the spin-flip optical transition of osmium complexes as a sensitizer. Moreover, we observed a remarkable enhancement of UC emission through the far-field effect by combining periodic plasmonic structures that exhibit strong light scattering (far-field effect) with TTA-UC thin films.

Free Research Field

ナノ材料化学，光化学

Academic Significance and Societal Importance of the Research Achievements

アップコンバージョン発光は，低エネルギー光を高エネルギー光に変換する技術であり，特に本研究で着目している三重項対消滅型アップコンバージョンは，原理上，太陽光でも駆動可能な技術である．それゆえ，当該アップコンバージョン素子を高性能化する技術の開発は，広範な太陽光デバイスの高性能化に直結する．すなわち，環境調和社会の実現に必須となる太陽光有効利用技術に大きく貢献可能な技術であり，本申請で得た三重項対消滅型アップコンバージョンの高性能化アプローチは，特に環境調和社会の実現にとって重要なものとなる．