May 16, 2022
Others
Achieving the world's highest level of blue organic EL performance with a new light emitting method - Selected as the best paper in "Display Week 2022" -
Idemitsu Kosan Co.,Ltd. (Headquarters: Chiyoda-ku, Tokyo, President: Shunichi Kito, hereinafter referred to as the "Company") has developed a new light emission method for OLED element using fluorescent blue materials, and has achieved the world's highest level of light emission. We have succeeded in increasing efficiency and longevity. Additionally, this result was selected as the best paper *1 at Display Week 2022, a symposium sponsored by the Society of Information Display, the world's largest academic society related to displays.
1. Summary of results
Among the light-emitting elements used in the red, green, and blue pixels that make up organic EL displays, the challenge is to further improve the performance and extend the lifespan of blue light-emitting elements. This result shows that a fluorescent element can be created by laminating two blue materials. *2 Charge recombination in the light emission process *3 and TTF ※Four By isolating the region that causes ※Five >14%) and a long-life OLED element.
This technology, which simultaneously improves luminous efficiency and extends lifespan compared to conventional technology, contributes to further power saving of organic EL displays and a reduction in environmental impact by improving the product life cycle.
[Performance overview]
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Method: Blue fluorescent OLED element using stacked emissive layers
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LT95 *6: 400 hours or more (as a result of driving conditions with a current density of 50mA/cm2)
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EQE: 14% (result of driving condition of current density 10mA/cm2)
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Chromaticity: (0.14, 0.08) (CIE1931 chromaticity coordinates)
2. Selected as the best paper for “Display Week 2022”
This result was selected as the best paper in the organic EL technology category at "Display Week 2022" held in San Jose, USA from May 9th.
Our company will continue to contribute to further improving the performance of OLED element and displays by developing high-performance organic EL materials.
Award ceremony at “Display Week 2022”
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Distinguished Paper “Realization of Ultra-High Efficient Fluorescent Blue OLED” (Satomi Tasaki, Kazuki Nishimura, Hiroaki Toyoshima, Tetsuya Masuda, Masato Nakamura, Yuki Nakano, Hiroaki Itoi, Emiko Kambe, Yuichiro Kawamura, Hitoshi Kuma) Journal of the Society for Information Display, Volume 30, Issue 5, pages:441-451 (2022) https://sid.onlinelibrary.wiley.com/doi/epdf/10.1002/jsid.1127
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Fluorescent element: A type of OLED element. In this method, the organic matter inside the device becomes a high-energy state (exciton) due to electricity, and the singlet excitons are used for light emission.
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Charge recombination region: A region where holes and electrons injected from the anode and cathode meet, creating a high-energy state in organic matter. Since the charge density inevitably increases, exciton quenching (deactivation phenomenon) tends to occur.
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TTF: Abbreviation for Triplet-Triplet Fusion. A process in which singlet excitons are generated by collisions between triplet excitons. Efficiency is improved by using triplet excitons, which are not used in fluorescent devices, for light emission.
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EQE: Abbreviation for External Quantum Efficiency. An indicator that shows what percentage of the electricity that enters the element is emitted to the outside of the element as light. The larger the value, the higher the luminous efficiency of OLED element.
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LT95: Continuous lighting time until initial brightness decreases by 5%
Regarding news release
contact information
Idemitsu Kosan Co.,Ltd. Public Relations Department Public Relations Division