申请人:BASF SE
公开号:US20160315274A1
公开(公告)日:2016-10-27
The present invention relates to organic light-emitting devices comprising (a) an anode, (i) a cathode, and (e) an emitting layer between the anode and cathode, comprising 2 to 40% by weight of a luminescent organometallic complex X having a difference of the singlet energy (E
S1
(X)) and the triplet energy (E
T1
(X)) of smaller than 0.2 eV [Δ(E
S1
(X))−(E
T1
(X))<0.2 eV], 0.05 to 5.0% by weight of a fluorescent emitter Y and 55 to 97.95% by weight of a host compound(s), wherein the amount of the organometallic complex X, the fluorescent emitter Y and the host compound(s) adds up to a total of 100% by weight and the singlet energy of the luminescent organometallic complex X (E
S1
(X)) is greater than the singlet energy of the fluorescent emitter Y (E
S1
(Y)) [(E
S1
(X))>E
S1
(Y)]. By doping, for example, an emitting layer containing a luminescent organometallic complex having a small S
1
-T
1
splitting, with a fluorescent emitter the emission decay time can significantly be shortened without sacrificing external quantum efficiency (EQE) because of very efficient energy transfer.