Organic light emitting diode (OLED) structure and method of making same
AssigneeOIS Optical Imaging Systems, Inc.
InventorsWillem den Boer, John Z. Z. Zhong, Scott V. Thomsen
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Abstract
An organic light emitting diode (OLED) array structure, and corresponding method of making same are provided. Each OLED pixel includes a first electrode on a substrate, a second electrode on a substrate, and an organic emission layer disposed between the first and second electrodes so as to emit visible light when a suitable potential is applied thereto by the electrodes. In accordance with certain embodiments of this invention, a step covering or coverage layer is provided over step or edge areas of the first electrode in order to reduce the structures susceptibility to breakdown at pixel edges thereby improving yields.
Claims16
An organic light emitting diode (OLED) comprising:
- a substrate;
- a first conductive electrode provided on said substrate, said first electrode defining a step area proximate a first edge thereof;
- a step covering layer provided on said substrate over at least a portion of said first electrode so that said step covering layer is located over said step area;
- an emission layer of organic material disposed on said substrate;
- a second conductive electrode provided on said substrate in a location such that said emission layer of organic material is disposed between said first and second conductive electrodes thereby forming said organic light emitting diode (OLED);
- and
- wherein said step covering layer in said step area minimizes the probability of breakdown of said emission layer at said step area.
A method of making an array of organic light emitting diodes (OLEDs), the method comprising the steps of:
- providing a substrate;
- depositing and patterning a first conductive layer on said substrate so as to form a plurality of first electrode portions;
- depositing a step covering layer on said substrate over said first electrode portions;
- photo-imaging the step covering layer by exposing the step covering layer to ultraviolet (UV) radiation in order to form a plurality of apertures in said step covering layer, each said aperture being defined over one of said first electrode portions;
- said photo-imaging allowing said step covering layer to remain adjacent at least one edge of each said first electrode portion in order to cover a step area;
- depositing an organic emission layer on said substrate over said step covering layer so that said emission layer contacts said first electrode portions through said apertures;
- and
- depositing a second conductive layer and patterning the second conductive layer into a plurality of second electrode portions so that in a plurality of pixel areas on the substrate said emission layer is disposed between one of said first electrode portions and one of said second electrode portions thereby forming the array of OLEDs.
Dependencies are inferred from the claim text.