This work investigates the manipulation of charge carriers and excitons in organic light-emitting diodes (OLEDs) to achieve high color purity and operational lifetime. By incorporating a thermally activated delayed fluorescence (TADF) assistant molecule with a deep LUMO into a bipolar host matrix, electron trapping is achieved while maintaining efficient hole transport. This shifts the recombination zone, mitigating interfacial quenching. The optimized OLED shows low driving voltage, high stability (LT95 > 430 h at 1000 cd m⁻²), and a high CIE y coordinate of 0.69, approaching the Rec.2020 standard.

Xun Tang, Tuul Tsagaantsooj, Tharindu P. B. Rajakaruna, Kai Wang, Xian-Kai Chen, Xiao-Hong Zhang, Takuji Hatakeyama, Chihaya Adachi