Exciplex energy transfer through spacer: White electroluminescence with enhanced stability based on cyan intermolecular and orange intramolecular thermally activated delayed fluorescence

Journal of Advanced Research

Matas Guzauskas¹  Jurate Simokaitiene¹  Dmytro Volyniuk¹  Juozas V. Grazulevicius¹  Galyna Sych¹  Hryhorii Starykov² 

[1] Department of Polymer Chemistry and Technology, Kaunas University of Technology, Barsausko 39, LT- 51423 Kaunas, Lithuania;Ivan Franko National University of Lviv, Kyryla I Mefodiya, 6, Lviv 79005, Ukraine;

关键词: Thermally activated delayed fluorescence;    Exciton energy transfer;    Exciplex;    White OLED;   

DOI  :  

来源: DOAJ

【 摘 要 】

Capability of exciplex energy transfer through a spacer was investigated using three exciplex-forming solid mixtures which contained the well-known electron accepting 2,4,6-tris[3-(diphenylphosphinyl)phenyl]-1,3,5-triazine and appropriately designed bipolar cyanocarbazolyl-based derivatives functionalized by attachment of carbazolyl, acridanyl or phenyl units. These novel cyanocarbazolyl-based derivatives were used as both the spacer and exciplex-forming donor. Efficient organic light-emitting diodes with electroluminescence in cyan-yellow region and maximum external quantum efficiency of up to 7.7% were fabricated owing to efficient thermally activated fluorescence (TADF) of the newly discovered exciplexes. An approach of exciton separation by the spacer between the studied exciplexes and selected orange TADF emitter was proposed for the fabrication of white electroluminescent devices with prolonged lifetime comparing to that of single-color exciplex-based devices. Exciplex-forming systems were tested for exciton separation between inter- and intramolecular TADF. Exciplex energy transfer through a spacer was observed on relatively long distance for one system due to the energy resonance between triplet levels of the exciplex and spacer. First time observed here exciplex energy transfer through a spacer can be useful for both improvement of device stability and obtaining of white electroluminescence.

【 授权许可】

Unknown