The device performance with the T14:F6 couple was lower than that of device with the T13:F6; this might be due to their different TADF behavior owing to the presence of different donor groups in T13 and T14. However, the EQE of the devices with T13:F6 couple was higher than those with each component. Recently, another red HF-OLED was reported using red-emitting BODIPY-based fluorescence emitter F2 and TADF emitter T3 (Table ). The fabricated HF-OLED with T3 and F2 shows EQEs of 19.4%.