申请人:Universal Display Corporation
公开号:US20160149139A1
公开(公告)日:2016-05-26
A composition formed of a mixture of two compounds having similar thermal evaporation properties that are pre-mixed into an evaporation source that can be used to co-evaporate the two compounds into an emission layer in OLEDs via vacuum thermal evaporation process is disclosed. The first and second compounds can have an evaporation temperature T
1
and T
2
, respectively, of 150 to 350° C., and the absolute value of T
1
−T
2
can be less than 20° C. The first compound can have a concentration C
1
in the mixture and a concentration C
2
in a film formed by evaporating the mixture in a vacuum deposition tool at a constant pressure between 1×10
−6
Torr to 1×10
−9
Torr, at a 2 Å/sec deposition rate on a surface positioned at a predefined distance away from the mixture being evaporated, where the absolute value of (C
1
−C
2
)/C
1
is less than 5%.