Universal Display Corporation
Organic electroluminescent materials and devices

Abstract:

A mixture containing three different compounds that is useful as a stable co-evaporation source material for a vacuum deposition tool is disclosed. The mixture comprises a first compound; a second compound; and a third compound that are all organic compounds and have different chemical structures from each other and each has an evaporation temperature T1, T2, and T3, respectively, in the range of 150 to 350.degree. C. T1, T2, and T3 differ from each other by less than 20.degree. C. The first compound has a concentration C1 in the first mixture and a concentration C2 in a film deposited by evaporating the first mixture in a high vacuum deposition tool under a predefined deposition condition where |(C1-C2)/C1| is less than 5%.