Development of high color rendering, wide viewing angle and high color purity, directional organic light emitting device using multi cathode structure

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K05957
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Device related chemistry
• Research Institution: Kanazawa Institute of Technology
• Principal Investigator: Akiyoshi Mikami 金沢工業大学, 工学部, 教授 (70319036)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 有機EL / 発光効率 / 光学解析 / マイクロキャビティ / 光取りだし

Outline of Final Research Achievements

We developed a multi-scale optical analysis method that connects electromagnetic optics and near-field optics in order to realize highly efficient OLED characteristics with high color purity and high directivity and high luminance white light emission characteristics with high color rendering and wide viewing angle characteristics. At the same time, the same method was applied to color organic devices to study improvement in color purity and luminous efficiency. As a result, the full width at half maximum of the emission spectrum of the RGB luminescence was reduced to about 1/2, the chromaticity coordinate of emission was improved, and the light extraction efficiency was improved to a range of 25 to 35%. Moreover, as a result of applying the same method to a white OLED with the combination of multi-cathode and light scattering layer, light extraction efficiency and power efficiency are improved, and color rendering and viewing angle are also improved.

Free Research Field

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Academic Significance and Societal Importance of the Research Achievements

本研究はマルチカソード構造を利用した高演色性・広視角特性の白色有機ＥＬ、並びに高色純度・高指向性の有機ＥＬディスプレイを実現する光学設計技術の開発であり、電力損失の主因である表面プラズモン効果の低減により高効率を維持したまま、照明装置やディスプレイ装置が要求する発光特性を実現できる。また、本研究で開発したマルチスケール解析手法は有機薄膜デバイスの光学理論および高性能化に向けた構造・材料の探索・設計に新たな学問的知見を与える。同研究成果は有機ＥＬ照明の高輝度化、並びに次世代4K8K-TV用のBT2020規格に適合した色再現範囲の広いカラー有機ＥＬディプレイの開発に寄与する。