Organic light-emitting diodes (OLEDs) play an important role in the new generation of flat-panel displays. Conventional OLEDs employing fluorescent materials suffer from a relatively low internal quantum efficiency (IQE) of ~37.5%. On the other hand, the IQE of OLEDs employing phosphorescent or thermally activated delayed fluorescence (TADF) materials can reach ~100%. However, phosphorescent and TADF materials exhibit broad emission peaks, whose typical full-width at half-maximum (FWHM) is 60–100 nm. We newly designed and synthesized organic molecules that exhibit ultrapure blue fluorescence based on TADF. An OLED device based on the new emitter exhibits ultrapure blue emission at 467 nm with an FWHM of 28 nm and an IQE of ~100%, which represent record-setting performance for blue OLED devices.
Program Information
JST PRESTO
Research Area “New Materials Science and Element Strategy”
Research Theme “Synthesis of Helical π-Conjugated Molecules Toward Next Generation Semiconductors”
Journal Information
Takuji Hatakeyama, Kazushi Shiren, Kiichi Nakajima, Shintaro Nomura, Soichiro Nakatsuka, Keisuke Kinoshita, Jingping Ni, Yohei Ono, and Toshiaki Ikuta. “Ultrapure Blue Thermally Activated Delayed Fluorescence Molecules: Efficient HOMO–LUMO Separation by the Multiple Resonance Effect”. Advanced Materials, Published online 11 February 2016, doi: 10.1002/adma.201505491.
Contact
[About Research]
Takuji Hatakeyama, Ph.D.
Associate Professor, School of Science and Technology, Kwansei Gakuin University
E-mail: 
URL: http://sci-tech.ksc.kwansei.ac.jp/~hatakeyama/index.html
[About Program]
Sofia Saori Suzuki
Green Innovation Group, Department of Innovation Research, JST
E-mail: 