US Patent 7842341 Purifying organic materials for physical vapor deposition

A method for evaporating a plurality of purified organic materials in a thermal physical vapor deposition system, comprising the steps of: mixing predetermined amounts of first and second organic materials to form a mixture of materials at a predetermined ratio; processing at least one of the organic materials at less than the sublimation temperature of the at least one of the organic materials before or after mixing to remove a first contaminant, wherein if processing is after mixing, the processing temperature is lower than the sublimation temperature of each of the organic materials; providing a thermal physical vapor deposition source; transferring the purified mixture of organic materials into the thermal physical vapor deposition source while maintaining the purified mixture of organic materials in a controlled, contaminant-free environment; and using the source to evaporate the purified mixture of organic materials.