RT Journal Article
T1 High triplet energy host materials for blue TADF OLEDs—A tool box approach
A1 Rodella, Francesco
A1 Bagnich, Sergey
A1 Duda, Eimantas
A1 Meier, Tobias
A1 Kahle, Julian
A1 Athanasopoulos, Stavros
A1 Köhler, Anna
A1 Strohriegl, Peter
AB The synthesis of stable blue TADF emitters and the corresponding matrix materials is one of the biggest challenges in the development of novel OLED materials. We present six bipolar host materials based on triazine as an acceptor and two types of donors, namely, carbazole, and acridine. Using a tool box approach, the chemical structure of the materials is changed in a systematic way. Both the carbazole and acridine donor are connected to the triazine acceptor via a para- or a meta-linked phenyl ring or are linked directly to each other. The photophysics of the materials has been investigated in detail by absorption-, fluorescence-, and phosphorescence spectroscopy in solution. In addition, a number of DFT calculations have been made which result in a deeper understanding of the photophysics. The presence of a phenyl bridge between donor and acceptor cores leads to a considerable decrease of the triplet energy due to extension of the overlap electron and hole orbitals over the triazine-phenyl core of the molecule. This decrease is more pronounced for the para-phenylene than for the meta-phenylene linker. Only direct connection of the donor group to the triazine core provides a high energy of the triplet state of 2.97 eV for the carbazole derivative CTRZ and 3.07 eV for the acridine ATRZ. This is a major requirement for the use of the materials as a host for blue TADF emitters.
PB Frontiers
SN 2296-2646
YR 2020
FD 2020-07
LK https://hdl.handle.net/10016/38056
UL https://hdl.handle.net/10016/38056
LA eng
NO We acknowledge funding through the EU Marie Sklodowska-Curie ITN TADFlife grant (GA. 812872). This work was also supported by the Universidad Carlos III de Madrid, the European Union's Seventh Framework Programme for research.
DS e-Archivo
RD 1 sept. 2024