Highly Horizontally Oriented BODIPY Emitters for Efficient BT. 2020 Red OLEDs via Low‐Polarity Multi‐Sensitization Strategy

ABSTRACT Achieving high‐efficiency and low roll‐off red organic light‐emitting diodes (OLEDs) that meet Broadcast Television 2020 (BT. 2020) standards remains a formidable challenge, due to the scarcity of narrowband red emitters exhibiting both short exciton lifetimes and desirable color purity. Herein, three boron‐dipyrromethene (BODIPY)‐derived narrowband red emitters (BDP1P, BDP1TPM, and BDP‐tBu) with high horizontal orientation are developed through vinyl‐bridged conjugation extension achieving bathochromic‐shifted emission (642–652 nm) while maintaining ultra‐narrow emission bandwidth (<30 nm). Furthermore, OLEDs are fabricated using a rational design strategy, employing a low‐polarity tricomponent multi‐sensitization host matrix, doped with BODIPY emitters in the emission layer. This design not only achieves a narrowband electroluminescence with minimal energetic loss during energy transfer but also facilitates accelerated exciton consumption, thereby ameliorating efficiency roll‐off at high luminance levels. Consequently, a remarkable external quantum efficiency (EQE) of 15.6% is achieved for the BDP1P‐based OLED, simultaneously with an ultralow roll‐off (EQE of 15.5% @ 1000 and 13.6% @ 10 000 cd m −2 ) and BT.2020‐compliant color coordinates (CIE: 0.708, 0.292), which represents one of the most advanced performance reported for red OLEDs based on traditional fluorescent emitters.