Dresden 2017 – wissenschaftliches Programm
CPP 50.14: Poster
Mittwoch, 22. März 2017, 18:30–21:00, P3
Efficient Deep-blue Pyridimidine-based TADF Emitters Using a Highly Twisted Molecular Skeleton — •Ryutaro Komatsu1, Tatsuya Ohsawa2, Hisahiro Sasabe1, 2, 3, Kohei Nakao1, Yuya Hayasaka1, and Junji Kido1, 2, 3, 4 — 1Department of Organic Materials Sience, — 2Faculty of Engineering, — 3Research Center for Organic Electronics (ROEL), — 4Frontier Center for Organic Materials (FROM), Yamagata University, 4-3-16 Jonan, Yonezawa, Yamagata, 992-8510, Japan
The development of efficient deep-blue emitters is one of the key issues in organic light-emitting devices (OLEDs). As a promising technology that realizes 100% conversion from electrons to photons, thermally activated delayed fluorescence (TADF) emitters have attracted considerable attention. However, only a few efficient deep-blue TADF emitters have been reported to date. Here, we molecularly manipulated the electronic excited state energies of pyrimidine-based TADF emitters to realize deep-blue emission. We then systematically investigate the relationships among the chemical structure and optical properties. The resultant novel pyrimidine emitters called Ac-XMHPMs (X = 1, 2, and 3) contain different numbers of bulky methyl substituents at acceptor moieties, increasing the excited singlet and triplet state energies. Among them, Ac-3MHPM, with a high triplet state energy of 2.95 eV exhibits a high peak external quantum efficiency (EQE) of 18% and an EQE of 10% at 100 cd/m2 with Commission Internationale de l'Eclairage chromaticity coordinates of (0.16, 0.15). These efficiencies are among the highest values to date for deep-blue TADF-OLEDs.