Above 30% external quantum efficiency in green delayed fluorescent organic light-emitting diodes.
Highly efficient green thermally activated delayed fluorescent organic light-emitting diodes with an external quantum efficiency of 31.2% were investigated by using 3-(3-(carbazole-9-yl)phenyl) pyrido[3',2':4,5]furo[2,3-b]pyridine (3CzPFP) derived from carbazole and pyrido[3',2':4,5]furo[2,3-b]pyridine. The host material showed well-matched photoluminescence emission with absorption of the green dopant material, (4s,6s)-2,4,5,6-tetra(9H-carbazol-9-yl)isophthalonitrile (4CzIPN) and harvested all excitons of 4CzIPN. The 3CzPFP:4CzIPN film exhibited high photoluminescence quantum yield of 100%, and the green delayed fluorescence device employing the 3CzPFP host showed high maximum quantum efficiency of 31.2 ± 0.5% at 1% doping after optimization of the device structure.
†Department of Polymer Science and Engineering, Dankook University, Gyeonggi-do 448-701, Korea.
Dong Ryun
DR
Lee
†Department of Polymer Science and Engineering, Dankook University, Gyeonggi-do 448-701, Korea.
Bo Seong
BS
Kim
†Department of Polymer Science and Engineering, Dankook University, Gyeonggi-do 448-701, Korea.
Chil Won
CW
Lee
‡School of Chemical Engineering, Sungkyunkwan University 2066, Seobu-ro, Jangan-gu, Suwon, Gyeonggi 440-746, Korea.
Yirang
Y
Im
‡School of Chemical Engineering, Sungkyunkwan University 2066, Seobu-ro, Jangan-gu, Suwon, Gyeonggi 440-746, Korea.
Kyoung Soo
KS
Yook
†Department of Polymer Science and Engineering, Dankook University, Gyeonggi-do 448-701, Korea.
Seok-Ho
SH
Hwang
‡School of Chemical Engineering, Sungkyunkwan University 2066, Seobu-ro, Jangan-gu, Suwon, Gyeonggi 440-746, Korea.
Jun Yeob
JY
Lee
bipolar host; delayed fluorescence; green fluorescent device; high quantum efficiency; high triplet energy