New blue phosphorescence from trifluorosulfonyl-substituted iridium complexes

Abstract For color-pure phosphorescence organic light emitting diodes (PHOLEDs), we synthesized the trifluoromethyl sulfonyl substituted ligand and two new blue Iridium complexes with perfluoro-sulfonyl group (SOCF 3 pic and SOCF 3 mpic). The both iridium complexes showed similar photophysical and thermal properties while the HOMO energy leves of two Iridium complexes slightly differnet to be −5.84 eV for SOCF 3 pic and −5.74 eV for 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 images of scattered X-ray intensity from surface to full depth for SOCF 3 pic-doped and SOCF 3 mpic-doped TCTA:4PTPS films were characterized for preferential orientation along the out-of-plane direction.