Oxadiazole derivatives as bipolar host materials for high-performance blue and green phosphorescent organic light-emitting diodes.

ABSTRACT: By combining two n-type groups, pyridine and oxadiazole, with one p-type carbazole group, two novel bipolar hosts, namely 2-(3-(9H-carbazol-9-yl)-[1,1'-biphenyl]-3-yl)-5-(pyridin-2-yl)-1,3,4-oxadiazole (PyOxd-mCz) and 2-(4'-(9H-carbazol-9-yl)-[1,1'-biphenyl]-3-yl)-5-(pyridin-2-yl)-1,3,4-oxadiazole (PyOxd-pCz) have been developed as hosts for blue and green phosphorescent organic light-emitting diodes (PhOLEDs). The two compounds exhibit similar HOMO levels of -5.64 eV for PyOxd-mCz and -5.63 eV for PyOxd-pCz and the same LUMO level of -2.60 eV. With a more twisted configuration due to meta connections, PyOxd-mCz possesses a higher triplet energy level (E _T = 2.77 eV) and more balanced carrier transport than PyOxd-pCz (E _T = 2.60 eV).

SUBMITTER: Wang Y 

PROVIDER: S-EPMC9072674 | biostudies-literature | 2019 Oct

REPOSITORIES: biostudies-literature