Organic Light-Emitting Component Coupling-Out Layer
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Solution Overview
Problem
Conventional organic light-emitting components, such as OLEDs, suffer from low light coupling-out efficiency due to waveguiding effects and absorption losses, with internal modes being difficult to couple out, and external measures like scattering films result in a milky appearance and limited efficiency of around 60-70%.
Innovation Solution
An organic light-emitting component with a high refractive index first organic coupling-out layer in optical contact with the light-generating layer stack, comprising an organic material with a second OLED functional material, arranged between the electrodes to minimize reflections and enhance light scattering, thereby improving light coupling-out efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional scattering films are applied to the outer side of the substrate to improve light coupling-out, then the coupling-out efficiency of external modes is improved to 60-70%, but internal modes cannot be coupled out and the appearance becomes milky or diffuse
Solution Approach 1:
Instead of applying scattering films to the outer side of the substrate (external coupling-out), the patent places the coupling-out layer on the inner side between the light-generating layer stack and the translucent electrode. This inverted approach enables both internal modes and external modes to be coupled out effectively while maintaining a smooth appearance, achieving coupling-out efficiency of approximately 80% or more without the milky appearance problem.
Solution Approach 2:
The patent introduces an organic coupling-out layer as an intermediary between the light-generating layer stack and the translucent electrode. This intermediate layer has specific optical properties (refractive index between 1.7 and 2.0) that enable effective coupling-out of light modes without causing scattering that would lead to milky appearance, thus mediating between the light generation and external observation.
2Loss of energy
If scattering films are applied externally to increase light coupling-out, then some light can be extracted, but the overall coupling-out efficiency remains limited and internal modes are lost
Solution Approach 1:
The patent moves the coupling-out function from the external dimension (outer side of substrate) to the internal dimension (between light-generating layer stack and translucent electrode). This dimensional shift allows the coupling-out layer to interact with light modes at their origin, enabling extraction of both internal and external modes that would otherwise be lost, thereby significantly improving overall light extraction efficiency to 80% or more.
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 significantly increases light coupling-out efficiency by up to 50% compared to conventional components, reduces waveguiding effects, and maintains a smooth appearance by avoiding external scattering films, while protecting the coupling-out layer from environmental influences.
Implementation Method 1
the first organic coupling-out layer... to minimize reflections and enhance light scattering, thereby improving light coupling-out efficiency
Implementation Method 2
there are arranged between the organic light-generating layer stack and the first organic coupling-out layer only layers and/or elements which have a refractive index that is greater than or equal to the layer-thickness-weighted average value of the refractive index of the organic light-generating layer stack
Data Source
AI summary
According to at least one embodiment, an organic light-emitting component includes a substrate, a first electrode arranged on the substrate, and a second electrode. An organic light-generating layer stack is arranged between the first and second electrodes and includes a first organic OLED functional material. A first organic coupling-out layer is in optical contact with the organic light-generating layer stack and includes an organic material containing a second organic OLED functional material. One of the first and second electrodes is translucent, and the first organic coupling-out layer is arranged on that side of the electrode that faces away from the organic light-generating layer stack.