Dual n-type units including pyridine and diphenylphosphine oxide: effective design strategy of host materials for high-performance organic light-emitting diodes.

ABSTRACT: By using pyridine and diphenylphosphine oxide (DPPO) as dual n-type units, two novel bipolar hosts, namely (5-(3,5-di(9H-carbazol-9-yl)phenyl)pyridin-3-yl)diphenylphosphine oxide (m-PyPOmCP), and (6-(3,5-di(9H-carbazol-9-yl)phenyl)pyridin-3-yl)diphenylphosphine oxide (p-PyPOmCP) are developed for blue and green phosphorescent organic light-emitting diodes (PhOLEDs). Direct linking of the dual n-type units not only pulls the LUMOs down, but also keeps the HOMO levels shallow, and leads to high triplet energies (2.78-2.86 eV) and small singlet-triplet energy differences (0.23-0.35 eV). Blue and green PhOLEDs are fabricated using FIrpic and Ir(ppy)₃ as dopants in the hosts. A low turn-on voltage of 2.6 V is achieved for the green PhOLEDs. The m-Py

SUBMITTER: Li W 

PROVIDER: S-EPMC5355805 | biostudies-literature | 2016 Nov

REPOSITORIES: biostudies-literature