OLED Light Source Index Bridging Elastomer
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Solution Overview
Problem
Organic light-emitting diodes (OLEDs) suffer from a significant wave guiding effect due to the difference in refractive indices between the glass substrate and the surrounding medium, resulting in less than 40% of generated light escaping to illuminate the intended area, which limits their efficiency for lighting applications.
Innovation Solution
An index bridging elastomer with a refractive index matching that of the OLED substrate and the intended target is used to eliminate wave guiding effects, enhancing light transmission by being applied between the OLED substrate and the target, such as human skin or lighting covers, while also acting as a thermal insulator and buffer layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If OLEDs use glass substrate with high refractive index, then structural strength and protection are improved, but wave guiding effect increases and light extraction efficiency deteriorates
Solution Approach 1:
The patent introduces an index-matching layer with refractive index intermediate between the glass substrate and air to eliminate total internal reflection. This intermediary layer acts as a mediator that gradually transitions the refractive index, allowing trapped light to escape while maintaining the glass substrate's structural integrity.
Solution Approach 2:
The patent modifies the optical parameters of the system by introducing materials with specific refractive indices. The index-matching layer changes the refractive index gradient at the substrate interface, transforming the wave guiding effect into effective light extraction without altering the substrate's mechanical properties.
2Illumination intensity
If OLEDs operate at high power, then illumination intensity is improved, but temperature rise increases and efficiency deteriorates due to wave guiding loss
Solution Approach 1:
The patent converts the previously harmful wave guiding effect (which caused light loss and heat generation) into a beneficial light extraction mechanism. By introducing the index-matching layer, the total internal reflection is eliminated, allowing high-power operation to produce intense illumination without excessive temperature rise, as the light energy is effectively extracted rather than converted to heat.
3Illumination intensity
If OLEDs use transparent substrate for light emission, then light transmission is improved, but wave guiding effect traps light and reduces illumination efficiency
Solution Approach 1:
The index-matching layer serves as an intermediary optical element that enables light to transition from the high refractive index substrate to the low refractive index air environment. This mediator layer eliminates the abrupt refractive index discontinuity that causes total internal reflection, allowing the transparent substrate to effectively transmit light without trapping energy.
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
This solution significantly improves light output, reduces driving power requirements, and minimizes temperature rise during operation by effectively transmitting most generated light to the intended area, while maintaining compatibility and safety with human skin and lighting materials.
Implementation Method 1
An index bridging elastomer with a refractive index matching that of the OLED substrate and the intended target is used to eliminate wave guiding effects, enhancing light transmission
Implementation Method 2
enhancing light transmission by being applied between the OLED substrate and the target, such as human skin or lighting covers, while also acting as a thermal insulator and buffer layer
Data Source
AI summary
An apparatus such as a light source is disclosed which has an OLED device and an index bridging elastomer disposed on the substrate or transparent electrode of said OLED device and on the exterior of said OLED device. The elastomer bridges the refractive index between the substrate and an intended target for said apparatus.