Very broad white-emission spectrum based organic light-emitting diodes by four exciplex emission bands.
White light is emitted by an organic light-emitting diode by inserting two blend layers of m-MTDATA:Al(DBM)(3) and TPD:Bphen between an m-MTDATA hole-transporting layer and a Bphen electron-transporting layer, where m-MTDATA, TPD, Al(DBM)(3), and Bphen are 4,4('),4('')-tris[methylpheny(phenyl)amino]-triphenylamine, N,N(')-bis(3-methylphenyl)-N,N(')-diphenylbenzidine, tris(dibenzoyl methane)-aluminum, and 4,7-diphenyl-1,10-phenanthroline molecules, respectively. The white-light spectrum consists of four broad bands that arise from blue-emitting TPD/Bphen, green-emitting m-MTDATA/Bphen, orange-emitting TPD/Al(DBM)(3), and red-emitting m-MTDATA/Al(DBM)(3) exciplexes, respectively, and strongly overlap at 400-760 nm. Any monomer emission is not generated. A high-color rendering index of 94.1, Commission Internationale de l'Eclairage-1931(x,y) coordinates of (0.33, 0.35), and correlated color temperature of 5477 K were obtained at 10 V. Discussion is given for the formation mechanism of the four exciplexes.
Key Laboratory of Excited State Processes, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China.
Jianzhuo
J
Zhu
Wenlian
W
Li
Liangliang
L
Han
Bei
B
Chu
Guang
G
Zhang
Dongfang
D
Yang
Yiren
Y
Chen
Zisheng
Z
Su
Junbo
J
Wang
Shuanghong
S
Wu
Taiju
T
Tsuboi