Synthesis, characterization, and photo- and electro-luminescence of new Ir(III) complexes with carrier transporting group-functionalized dibenzoylmethane ligand for green phosphorescent OLEDs

• Two new iridium(III) complexes containing the carrier transporting group-functionalized dibenzoylmethane as ancillary ligands were synthesized and characterized.
• The complexes exhibit strong yellow-green emissions in the solution and solid state.
• The doped light-emitting devices using the Ir(III) complexes as dopants were fabricated, and yellow–green electroluminescence were observed.

Two new iridium(III) complexes containing the coumarin derivatives as cyclometalated ligands (L) and the carrier transporting group-functionalized dibenzoylmethane as ancillary ligands have been successfully synthesized and characterized. The X-ray crystal structure analyses of the free ligands and the complex containing a carbazole-functionalized dibenzoylmethane as ancillary ligand were described. The photophysical properties of the Ir(III) complexes were examined via ultraviolet-visible, photoluminescence spectroscopic spectra. The good thermal stability of the Ir(III) complexes was demonstrated by the thermogravimetric analysis. The doped light-emitting devices using the Ir(III) complexes as dopants were fabricated. The devices based on the complex containing a carbazole-functionalized dibenzoylmethane as ancillary ligand possess better performance as compared with the devices fabricated by the complex containing a 1,3,4-oxadiazole-functionalized dibenzoylmethane as ancillary ligand. The devices based on the former Ir(III) complex with a 15 wt% doping concentration exhibit a maximum efficiency of 13.8 cd/A and a maximum brightness of 4955.7 cd/m2.

Figure optionsDownload as PowerPoint slideTwo new iridium(III) complexes containing the coumarin derivatives as cyclometalated ligands (L) and the carrier transporting group-functionalized dibenzoylmethane as ancillary ligands, Ir(L)2(DBM-Cz) and Ir(L)2(DBM-Ox), have been successfully synthesized for fabricating the doped light-emitting devices. The devices based on the complex Ir(L)2(DBM-Cz) possess better performance as compared with the devices fabricated by the complex Ir(L)2(DBM-Ox).