Blue organic light-emitting diodes based on thermally activated sensitized fluorescence

As a revolutionary display technology, organic light-emitting diodes (OLEDs) have achieved remarkable progress in both scientific research and industrial applications. However, simultaneously achieving high efficiency and long lifetime in blue OLED devices remains a critical challenge that hinders their performance breakthroughs and industrial development. The emergence of the thermally activated sensitized fluorescence (TSF) technology offers a promising solution to this issue. By utilizing thermally activated delayed fluorescence (TADF) sensitizers to excite narrowband fluorescent emitters, TSF-OLED can achieve 100% exciton utilization efficiency, along with high color purity and long-lived blue emission. This review summarizes recent research advances in the application of TSF technology to blue OLED devices, covering innovations in emitting mechanisms, molecular design of sensitizers and narrowband emitters, as well as device optimization. Finally, the current core challenges of this technology are discussed, and future development directions are proposed.