Orange-emitting supramolecular phosphorescent polymer with different counterions for polymer light-emitting diodes

摘要

Several novel orange emission supramolecular phosphorescent polymers (SPPs) with different counterions of PF6-, Br and BIm(4)(-) have been developed for polymer light-emitting diodes. The formation of SPPs, utilizing efficient non-bonding assembly of dibenzo-24-crown-8-tethered iridium complex and dibenzylammoniumfunctionalized fluorene-dibenzothiophene-S,S-dioxide cooligomer, are monitored by H-1 NMR and viscosity measurement. The influences of different counterions on the optical, thermal and electroluminescent (EL) properties of the resulting SPPs, as well as the supramolecular assembly behavior are investigated in detail. These SPPs display high glass transition temperatures of ca. 100 degrees C. The single-emissive-layer PLED with SPP-PF6 exhibits the highest device efficiency of 12.32 cd A(-1) with the Commission Internationale de L'Eclairage (CIE) coordinates of (0.57, 0.43). More importantly, owing to "spacer" effect of the large BIm(4)(-) counterion, the device based on SPP-BIm(4)(-) show very low efficiency roll-off.