Organic Light Emitting Device Having Multiple Separate Emissive Layers
AssigneeThe Regents of the University of Michigan
InventorStephen R. FORREST
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Abstract
An organic light emitting device having multiple separate emissive layers is provided. Each emissive layer may define an exciton formation region, allowing exciton formation to occur across the entire emissive region. By aligning the energy levels of each emissive layer with the adjacent emissive layers, exciton formation in each layer may be improved. Devices incorporating multiple emissive layers with multiple exciton formation regions may exhibit improved performance, including internal quantum efficiencies of up to 100%.
Claims25
A device comprising:
- an anode;
- a cathode;
- and
- a stacked emissive region disposed between the anode and the cathode, the stacked emissive region comprising:
- a first organic emissive layer;
- a second organic emissive layer;
- and
- a third organic emissive layer;
- wherein:
- the first organic emissive layer has an emission peak different from at least one of the second emissive layer and the third emissive layer;
- and
- each of the organic emissive layers defines an exciton formation region.
An organic optoelectronic device, comprising:
- a first organic emissive layer comprising a first host and a first dopant adapted to emit light having a first spectrum;
- a second organic emissive layer comprising a second host and a second dopant adapted to emit light having a second spectrum, the second host having a LUMO between and aligned to the LUMO of the first host and the LUMO of the first dopant;
- and
- a third organic emissive layer comprising a third host and a third dopant adapted to emit light having a third spectrum, the third host having a LUMO between and aligned to the LUMO of the second host and the LUMO of the second dopant.
A method of fabricating an optoelectronic device, comprising:
- obtaining a substrate;
- depositing a first electrode over the substrate;
- depositing a first doped organic emissive layer over the first electrode;
- depositing a second doped organic emissive layer over the first emissive layer;
- depositing a third doped organic emissive layer over the second emissive layer;
- and
- depositing a second electrode over the third emissive layer;
- wherein each of the emissive layers defines a separate exciton formation region.
Dependencies are inferred from the claim text.