Highly efficient fluorescent and hybrid white organic light-emitting diodes based on a bimolecular excited system

A bimolecular excited system is considered as a promising candidate for developing white organic light-emitting diodes (WOLEDs) with reduced phosphorescent components. However, for actualizing high-performance WOLED, little attention has been paid to electromers compared to exciplexes. Herein, we construct the bimolecular excited system to prepare fluorescent WOLEDs by combining the electromer emission with the exciplex emission, achieving a maximum power efficiency of 11.8 lm/W with a color rendering index (CRI) of over 80. Furthermore, phosphorescent dopants are doped into an exciplex host to construct hybrid WOLEDs. The fabricated complementary-color and three-color devices achieve maximum efficiencies of 55.3 cd/A (46.8 lm/W) and 34.1 cd/A (26.8 lm/W), respectively. The spectral coverages of WOLEDs are broadened by the bimolecular excited system, and CRIs are further improved at high luminance. Our strategy may bring light to the future development of highly efficient WOLEDs with economy and sustainability.