• • Auxiliary ligand engineering boosts PLQY from 53.6% (pic) to 93.6% (3-ppca) and 97.2% (3-iqca) in CH2Cl2, directly translating to higher device efficiency and reduced non-radiative losses.
• • Solution-processed OLEDs based on (4-tfmptp)2Ir(3-iqca) achieve a maximum EQE of 31.4% and current efficiency of 91.4 cd A−1, surpassing typical vacuum-deposited orange phosphorescent devices and enabling low-cost large-area fabrication.
• • The 3-iqca device exhibits a 13% relative improvement in EQE over the 3-ppca device (31.4% vs. 27.8%), highlighting the critical role of extended π-conjugation and rigidity in the auxiliary ligand for charge balance and exciton confinement.
• • Emission peaks remain at ~568 nm across all complexes, ensuring color purity for orange OLEDs; the high PLQY and solution processability address the trade-off between efficiency and manufacturability in phosphorescent OLEDs.