96 / 2023-09-28 20:05:36

Phosphine Oxide Materials for White OLEDs

TADF,Phosphine oxide,OLED

Phosphorus Material Chemistry and Applied Science > 1) Phosphorus chemistry in material science

White thermally activated delayed fluorescence (TADF) materials and devices emerge rapidly.^[1] TADF materials based on organic molecular systems endow the devices with the merits of low cost, sustainability and environmental friendliness and so on. Therefore, white TADF diodes have the huge potential in daily lighting applications. However, the large polarity, serious quenching and marked dependence on device structures of TADF molecules induce the big challenges in developing high-performance TADF white OLEDs (WOLED). To avert these issues, most of TADF WOLEDs adopted complicated device structures of multiple hosts and emitting layers (EML).

Based on our previous works about blue TADF materials and devices, in recent years, we further realized high-performance single-EML TADF WOLEDs, through optimizing excite-state characteristics and aggregation behaviors of hosts and blue TADF molecules, and tuning carrier and exciton allocation processes between blue and yellow dopant.^[2] The maximum external quantum efficiencies were beyond 20%, accompanied by effectively suppressed efficiency roll-offs, reaching the state-of-the-art levels of white phosphorescent OLEDs.