Elucidation of the characteristics of doublet-based emission: Can radicals develop highly-efficient EL devices?

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K13973
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Functional solid state chemistry
• Research Institution: The University of Tokyo
• Principal Investigator: Tetsuro Kusamoto 東京大学, 大学院理学系研究科(理学部), 助教 (90585192)
• Research Collaborator: Evans Emrys
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: ラジカル / 発光 / 二重項 / スピン

Outline of Final Research Achievements

We tackled to achieve high energy-efficiency in electroluminescent devices by using highly stable organic radicals as the emitters. What we have elucidated are shown here: (1) The photonic properties of the radicals can be modulated by chemical stimuli and appropriate molecular design, while the emission quantum yield is not simply controlled and is affected by the strength of the chemical bonds as well as the flexibility of the molecular structure. (2) Coordination to metal ions enables to vary or enhance the photofunction of radicals. (3) The radical developed in this study displays electroluminescence in the device.

Free Research Field

分子物性化学

Academic Significance and Societal Importance of the Research Achievements

これまでラジカルは分解しやすく（＝化学反応性が高く）光らない物質として知られてきた。本研究では、これらの固定概念を覆す「光る安定ラジカル」を様々に創出できた点が、学術的に重要な成果である。さらに新たに開発したラジカルをデバイス中で発光させることができた。これは高エネルギー効率な発光デバイス実現へつながる重要な成果であり、学術的のみならず社会的にも意義深い。