Chiral Iridium complexes are very important for the preparation of
circularly polarized light emitting diodes (CP-OLEDs). Three novel
Iridium(III) complexes, Ir(dnfppy)2(Cl/pyrrole), Ir(dfppy)2(dpp) and
Ir(tfmqz)2(sdpp) have been synthesized and characterized, respectively.
These Iridium(III) complexes emitted deep-blue, blue and red
photoluminescence with high quantum yields, for
((Ir(dnfppy)2(Cl/Pyrrole): λmax=447 nm, F=62.4%; Ir(dfppy)2(dpp):
λmax=467 nm, F= 25%; Ir(tfmqz)2(sdpp): λmax=609 nm, F=73.7%). Compared
with Ir(dnfppy)2(Cl/pyrrole), HOMO energy level of Ir(dfppy)2(dpp) and
Ir(tfmqz)2(sdpp) was calculated to be −5.71/-5.73 eV, and LUMO energy
level increased to be -2.75/-3.36 eV, respectively. CD spectra of two
pairs of the enantiomers for Ir(dfppy)2(dpp) or Ir(tfmqz)2(sdpp)
displayed symmetry with opposite polarization between 300 and 600 nm.
The maximum external quantum efficiency (EQEmax) of OLEDs based on
Ir(tfmpqz)2(sddp) was 13.8%, showing a relatively low efficiency
roll-off with the EQE of 10.7% at 5000 cd/m2.