Blue and blue-green PhOLEDs prepared with neutral heteroleptic iridium(Ⅲ) complexes comprising substituted pyridine-1,2,4-triazoles as the ancillary ligands

摘要

Two neutral heteroleptic iridium(Ⅲ) complexes bearing substituted pyridine 1,2,4-triazoles as the ancillary ligands have been designed and investigated as emitters for PhOLEDs. Interestingly, blue and blue-green devices were obtained with the two complexes. Best devices were obtained with C_1 and reached a maximum brightness of 10,200 cd/m~2, a current efficiency of 4.3 cd/A at an operation voltage of 7.9 V while exhibiting the unusual low turn-on voltage of only 2.8 V. UV-visible absorption and pho-toluminescence spectroscopy as well as the cyclic voltammetry of the two iridium(Ⅲ) complexes were also investigated.