OLED Anode Reforming Layer for Impurity Diffusion Control
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Solution Overview
Problem
Conventional anode electrodes in organic electroluminescent display devices have unstable chemical structures, leading to impurity diffusion and reduced lifetime, and require costly vapor deposition methods for reforming layers, which are also physically and chemically unstable.
Innovation Solution
An organic electroluminescent display device with an anode electrode covered by a solution-coated ultra-thin polymer film, using soluble, heat-resistant, or fluorine-based polymers with functional groups, applied via methods like spin coating, dip coating, or spray coating, to enhance stability and interface properties without high-cost equipment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional ITO anode electrode is used, then transparency and conductivity are improved, but chemical stability deteriorates causing impurity diffusion
Solution Approach 1:
A polymer reforming layer is introduced as an intermediary between the ITO anode electrode and the organic emission layer. This reforming layer acts as a barrier that prevents impurity diffusion from the ITO into the organic layer while maintaining the electrical and optical properties needed for device operation.
Solution Approach 2:
The anode structure is transformed from a single material (ITO) to a composite structure consisting of ITO combined with a polymer reforming layer. This composite approach leverages the conductivity and transparency of ITO while adding the chemical stability and barrier properties of the polymer layer.
2Reliability
If conventional vapor deposition or plasma-polymerization methods are used to form reforming layers, then hole injection is improved, but manufacturing cost and equipment complexity increase
Solution Approach 1:
The invention replaces complex vacuum-based vapor deposition equipment or plasma-polymerization equipment with simple solution coating methods. The polymer reforming layer is applied by dissolving polymer material in a solvent and coating it onto the ITO electrode using conventional coating techniques, eliminating the need for expensive specialized equipment.
Solution Approach 2:
The invention uses a simple, inexpensive polymer solution that can be applied via low-cost coating methods. This approach sacrifices the long-term stability of complex deposition equipment in favor of using inexpensive, easily applicable materials and methods that achieve the same functional result.
3Reliability
If polymer reforming layers are formed by vapor deposition or plasma-polymerization, then interface properties are improved, but physical and chemical stability deteriorates over time
Solution Approach 1:
The invention changes the fundamental parameters of the reforming layer formation process - using solution-based polymer coating instead of vapor deposition or plasma-polymerization. This parameter change results in a reforming layer with superior physical and chemical stability while maintaining good interface properties with the organic emission layer.
Data Source
AI summary
An organic electroluminescent display (OLED) device having an anode electrode covered with a solution-coated ultra-thin polymer film (reforming layer) is disclosed. In one embodiment, an OLED device includes a substrate having a first anode electrode formed thereon. The first anode electrode is covered with an ultra-thin polymer film (reforming layer). An organic emission layer is formed over an upper surface of the reforming layer, and a second cathode electrode is formed over the organic emission layer. The reforming layer is made of a material selected from a general polymer that is a soluble polymer, a heat resistant polymer, and a fluorine-based polymer having one or more functional groups. The solution coating methods which may be used to apply the reforming layer include a spin coating method, a doctor blade method, a dip coating method, a roll coating method, a spray coating method, and an ink jet method.