ORGANIC ELECTROLUMINESCENT MATERIALS AND DEVICES

摘要

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.

主权项

1. A composition comprising: a mixture of a first compound and a second compound;
wherein the first compound has a different chemical structure than the second compound; wherein the first compound is capable of functioning as a phosphorescent emitter in an organic light emitting device at room temperature; wherein the first compound has an evaporation temperature T1 of 150 to 350° C.; wherein the second compound has an evaporation temperature T2 of 150 to 350° C.; wherein absolute value of T1-T2 is less than 20° C.; wherein the first compound has a concentration C1 in said mixture and a concentration C2 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 position at a predefined distance away from the mixture being evaporated; and wherein absolute value of (C1−C2)/C1 is less than 5%.