Comprehensive study on operational lifetime of organic light-emitting diodes: effects of molecular structure and energy transfer

Abstract

Abstract Organic light-emitting diodes (OLEDs) have been studied as a key technology for next-generation displays. Although OLEDs with internal quantum efficiencies of approximately 100% have been achieved using phosphorescent or thermally activated delayed fluorescent (TADF) emitters, little is known about the correlation between the molecular structure of emitters and the lifetime of OLEDs. Here we observed the effect of the molecular structure on the lifetime of OLEDs by utilizing the efficient energy transfer from TADF materials to phosphorescent emitters. We found that specific molecular structures are effective in extending the stability of TADF materials and the OLEDs fabricated using these materials.