Patent ID: 6384528
Filing Date: 2002-05-07
Classification: H01L

Abstract:
An electroluminescent device comprising:a first charge-carrier injecting layer for injecting positive charge-carriers; a second charge-carrier injecting layer for injecting negative charge-carriers; a layer of a first organic material located between the charge-carrier injecting layers; and located between the layer of the first organic material and one of the charge-carrier injecting layers; a first light-emissive region comprising a light-emissive second organic material having an energy-gap less than that of the first organic material; and a second light-emissive region comprising a mixture or a blend of a first component of a light-emissive third organic material having an energy-gap greater than that of the first organic material, and a second component having at least one energy level off-set from that of the first component; such that when charge-carriers are injected in the first light-emissive region by the charge-carrier injecting layers light is emitted principally from the second organic material and when charge-carriers are injected in the second light-emissive region by the charge-carrier injecting layers light is emitted principally from the third organic material.