am7b10914_si_001.pdf (630.19 kB)
An Exciplex Host for Deep-Blue Phosphorescent Organic Light-Emitting Diodes
journal contribution
posted on 2017-10-02, 00:00 authored by Hyoungcheol Lim, Hyun Shin, Kwon-Hyeon Kim, Seung-Jun Yoo, Jin-Suk Huh, Jang-Joo KimThe use of exciplex
hosts is attractive for high-performance phosphorescent organic light-emitting
diodes (PhOLEDs) and thermally activated delayed fluorescence OLEDs,
which have high external quantum efficiency, low driving voltage,
and low efficiency roll-off. However, exciplex hosts for deep-blue
OLEDs have not yet been reported because of the difficulties in identifying
suitable molecules. Here, we report a deep-blue-emitting exciplex
system with an exciplex energy of 3.0 eV. It is composed of a carbazole-based
hole-transporting material (mCP) and a phosphine-oxide-based electron-transporting
material (BM-A10). The blue PhOLEDs exhibited maximum external quantum
efficiency of 24% with CIE coordinates of (0.15, 0.21) and longer
lifetime than the single host devices.