OLED Top Electrode Passages and Organic Current Distribution Layer
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Solution Overview
Problem
Existing organic light-emitting diodes (OLEDs) face challenges with non-transparent substrates, including low conductivity, susceptibility to reactive ions, mechanical instability, and interference effects leading to distorted light spectra, especially when emitting white light, due to the use of traditional transparent top electrodes like ITO and thin metal layers.
Innovation Solution
An organic optoelectronic component with a top electrode featuring passages and an organic current distribution layer that extends into the light-emitting region, ensuring even light generation by allowing charge-carrier recombination across the entire area, including passages, and utilizing thick metal layers for enhanced stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If passages are provided in the top electrode to enable light emission through the top, then light can be generated in the light-emitting region, but non-shining sections appear in the range of the passages, adversely affecting the shining impression of the component
Solution Approach 1:
An organic current distribution layer is introduced as an intermediary between the top electrode with passages and the light-emitting region. This layer extends into the passage regions and makes electrical contact with both the top electrode and the light-emitting region, ensuring that charge carriers are supplied to areas beneath the passages, thereby eliminating non-shining sections and achieving homogeneous light emission across the entire component surface.
2Illumination intensity
If traditional transparent top electrodes like ITO are used, then transparency is achieved, but the conductivity is low resulting in voltage drop and lateral inhomogeneous light emission
Solution Approach 1:
The top electrode structure is designed as a composite system combining a transparent electrode material (such as ITO or thin metal layers) with an organic current distribution layer. This composite structure leverages the transparency of the electrode material while the organic layer provides enhanced conductivity and uniform charge carrier distribution, eliminating voltage drops and ensuring homogeneous light emission across the component.
3Illumination intensity
If thin metal layers like 15 nm silver are used as transparent top electrodes, then minimal absorption and sufficient transparency are achieved, but the layers are not mechanically stable and often lead to premature failure due to tear or crack
Solution Approach 1:
The fragile thin metal layer is combined with the organic current distribution layer to form a composite electrode structure. The organic layer acts as a mechanically stable substrate that supports the thin metal layer, preventing tears and cracks while maintaining the transparency and electrical conductivity properties of the metal layer.
Solution Approach 2:
The organic current distribution layer serves as a flexible, mechanically robust film that underlies the fragile thin metal layer. This organic film provides the necessary mechanical stability and flexibility, allowing the thin metal layer to maintain its transparency function without suffering from mechanical failure.
4Strength
If thick metal layers are used for the top electrode to improve mechanical stability, then stability is enhanced, but the high reflectivity leads to difficulties controlling interference effects and distortion of the emissions spectrum
Solution Approach 1:
Instead of using a single thick metal layer, the patent employs a composite structure with a thin transparent metal layer combined with an organic current distribution layer. This composite approach provides sufficient mechanical stability through the organic layer while the thin metal layer maintains low reflectivity, allowing for better control of interference effects and accurate reproduction of the emissions spectrum.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution provides homogeneous light emission and improved stability by optimizing the top electrode's design with passages and an organic current distribution layer, enhancing conductivity and mechanical stability while minimizing interference effects, thus enabling effective light generation across a broader wavelength range.
Implementation Method 1
An organic current distribution layer also extends into the region containing the passages, said layer making electrical contact with the top electrode and the light-emitting region
Implementation Method 2
light can be generated in a light-emitting region by the application of electrical energy to the base electrode and the top electrode
Data Source
AI summary
The invention relates to an organic optoelectronic component comprising a base electrode, a top electrode that is provided with passages and an arrangement of organic layers, which is formed between the base electrode and the top electrode and makes electrical contact with said electrodes. In said component, light can be generated in a light-emitting region by the application of electrical energy to the base electrode and the top electrode. An organic current distribution layer also extends into the region containing the passages, said layer making electrical contact with the top electrode and the light-emitting region.