Abstract

Highly efficient blue electrophosphorescence in organic light-emitting device (OLED) has been achieved by employing a weak electron transporting material compacting layer without an additional energy barrier for charge transporting by inserting a hole blocking layer between the electron transporting layer and the emitting material layer. Iridium (III) bis[(4,6-difluorophenyl)-pyridinato-N, C²’]picolinate (FIrpic) was used as the phosphorescent emitter, and over 20% of maximum external quantum efficiency was achieved. This result contradicts the conventional notion that a weaker ET material in an OLED results in lower efficiency, which shows an alternative way to design electron transporting materials for blue electrophosphorescent devices.

© 2011 Optical Society of America