Multi-color emission organic EL diode with vapor deposited multi-layer structure

Multi-color organic electroluminescent (EL) diodes have been realized in vapor deposited multi-layered EL device, which emit blue, green or red. The EL device consists of multi-layer structure of dye molecules which emit blue, green or red. EL emission color in the multi-layered device can be changed by applying opposite bias field. The mechanism of color change has been discussed in terms of carrier injection and carrier transport mechanism in the diode.