Direct vapor jet printing of three color segment organic light emitting devices for white light illumination

Organic-vapor jet printing (OVJP) is used to directly pattern small molecular weight electrophosphorescent white organic light-emitting devices (WOLEDs) consisting of parallel stripes of separate red, green, and blue OLEDs. The spatial patterning of the WOLEDs with peak forward viewing external quantum and luminous efficiencies of 7.1±0.3% and 7.0±0.4lm∕W, respectively, is accomplished by transporting the vapors of organic semiconductors through a nozzle to a translating sample substrate. Using multiple color segments to generate white light allows for the individual optimization of each color, is continuously color tunable, and can be used to compensate for differential aging of the constituent dopants. The theory and experimental results of WOLED printing via OVJP are discussed.