Abstract:The development of high‐efficiency orange phosphorescent organic light‐emitting diodes (PhOLEDs) with reduced efficiency roll‐off offers significant benefits, enabling a more simplified method for producing white‐OLEDs through the combination of sky blue and orange OLEDs, in contrast to the conventional use of three primary colors. Herein, we have designed and synthesized two hosts with 9‐(4‐(14H‐dibenzo[a,j]xanthen‐14‐yl)phenyl)‐9H‐carbazole (XaPCz) and 10‐(4‐(14H‐dibenzo[a,j]xanthen‐14‐yl)phenyl)acridin‐9(10H)‐one (XaPAc) derivatives. The singlet and triplet energies for XaPCz and XaPAc are S1=3.65, 3.12 eV, and T1=2.67, 2.70 eV, respectively. These materials are employed as hosts for orange PhOLEDs using bis(2‐phenylquinoline) (acetylacetonate) iridium (III) [Ir(pq)3] as an emitter. XaPCz demonstrates maximum external quantum efficiency (EQEmax) of 20.5 %, and XaPAc shows EQEmax of 22.3 % with Commission Internationale de l′Eclairage (CIE) coordinates of (0.53, 0.46) and (0.54, 0.45), respectively. In addition, the XaPAc‐based device shows a lower turn‐on voltage (2.5 V) and high‐power efficiency of 60.0 lm/W. More importantly, both device shows reduced roll‐off and retain more than 94 % of EQEmax at 1,000 cd/m2. The XaPAc‐based device maintains an EQE of 17.9 % even at 10,000 cd/m2.