New blue phosphorescence from trifluorosulfonyl-substituted iridium complexes

Abstract

For color-pure phosphorescence organic light emitting diodes (PHOLEDs), we synthesized the trifluorometh) sulfonyl substituted ligand and two new blue Iridium complexes with perfluoro-sulfonyl group (SOCF(3)pic an, SOCF(3)mpic). The both iridium complexes showed similar photophysical and thermal properties while the HON energy leves of two Iridium complexes slightly differnet to be -5.84 eV for SOCF(3)pic and -5.74 eV fa SOCF(3)mpic, respectively. The device with the SOCF(3)mpic dopant exhibited higher device efficiencies of 7.17 cd A and 3.7% compared to that with the SOCF(3)pic dopant (4.03 cd/A and 2.78%). Two-dimensional GIXD image of scattered X-ray intensity from surface to full depth for SOCF(3)pic-doped and SOCF(3)mpic-doped TCTA:4PTP films were characterized for preferential orientation along the out-of-plane direction.