The Design, Synthesis And Performance Research Of TADF Materials

In this thesis, we focus on the hot point and forward position field of organic light-emitting diodes(OLEDs), a new light-emitting mechanism called thermally activated delayed fluorescence(TADF). We have studied their key issues and then a series of TADF materials have been designed and synthesized. Previously, researchers have reported that the theoretical limit of internal quantum efficiency for OLEDs is 25%. However, TADF materials show nearly 100% internal quantum efficiency which break the limitation above. With the strength of simple structure, highly efficient TADF materials will become the main direction of OLED development. Main points are listed as follow.1. In the first chapter, we review the development history and application of OLED and introduce the TADF briefly.2. In the second chapter, An Cz has been designed and synthesized on the basis of anthraquinone and carbazole. TADF and small ΔEST has been achieved by optimizing molecular structures. The external quantum efficiency(EQE) is 14.4% and CIE is(0.45,0.53). Using m CP and CBP doped luminescent layer both achieved excellent results3. In the third chapter, AnPTZ has been designed and synthesized on the basis of anthraquinone and carbazole. TADF and small ΔEST has been achieved by optimizing molecular structures. The EQE is 0.6% and CIE is(0.44,0.53).4. In the fourth chapter, DAn Cz has been designed and synthesized on the basis of anthraquinone and carbazole. TADF and small ΔEST has been achieved by optimizing molecular structures. Then we characterize the Photophysics properties of DAn Cz.5. In the final chapter, we review the important properties of the materials above and predict the future of TADF materials.