| 主权项 |
1. A microcavity narrow band organic light emitting diode (OLED) device having enhanced light emission, comprising,
a) a substrate; b) a microcavity having a selected cavity length defined over one substrate by, in sequence, a dielectric minor made with a quarter wave stack (QWS), a metallic transmissive electrode, an organic electroluminescent (EL) layer comprising of a hole injection layer (HIL), a hole transporting layer (HTL), an emissive layer (EML), an electron transporting layer (ETL), an electron injection layer (EIL), and a metal electrode, wherein the QWS comprises of a defined number of alternating high refractive index and low refractive index QWS pairs and wherein a maximum reflectivity of QWS mirrors is provided by selection of dielectric materials; wherein one metallic electrode layer is light transmissive and the second metal electrode layer is substantially opaque and reflective; wherein the organic electroluminescent (EL) layer comprises at least one host material selected from the class of aryl amines and aryl-substituted carbazole compounds, aryl substituted oxadiazoles, aryl-substituted triazoles, aryl substituted phenanthrolines and metal quinoxolates and at least one phosphorescent emitter material dispersed in the at least one host material and selected from the class of phosphorescent dyes comprising derivatives of cyclometalated metal complexes having a narrow emission spectrum bandwidth, and wherein a full width at a half maximum emission intensity is less than 40 nm, so that one of red, green, or blue light is generated in the EML layer. wherein the position of the EML to the metal electrode layer that is opaque and reflective is defined; wherein the selected cavity length of the microcavity OLED device is tuned to provide a resonance condition for emission of one of red, green, or blue light through the light transmissive electrode layer and having the improved light extraction efficiency; wherein the light extraction efficiency of the device is tuned by adjusting the spacing between a metallic transmissive electrode and the metal electrode layer that is opaque and reflective, and the selected cavity length is modified by adjusting a thickness of the light transmissive electrode layer and a thickness of the organic electroluminescent layer (EL), or a combination thereof. |
