Title:
Model of exciton quenching of Ir(ppy)₃ with hole measured by time-resolved luminescence spectroscopy

Speaker(s):
Shiho Oyama, Heisuke Sakai, Hideyuki Murata
School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa 923-1292, Japan
E-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

Abstruct:
Charge carriers and excitons always coexist inside a light emitting layer of working organic light-emitting devices (OLEDs). Thus, the excitons in the layer can be quenched via photophysical processes such as exciton-charge (polaron) interactions, exciton-exciton interactions. These interactions are observed as a decrease in efficiency with increasing current density particularly in phosphorescent OLEDs and this is called efficiency roll-off. In this work, time-resolved PL spectroscopy of holes-only device is employed to clarify the exciton quenching dynamics about triplet-polaron quenching. The results suggested that a region of high concentrated hole expands as increasing current density.