Quantum Dot Display Panel With Dual Emission Layers for Color Conversion
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Solution Overview
Problem
Conventional display panels utilizing quantum dots as color filters have low light conversion efficiency, which affects the overall performance of color reproduction in subpixels.
Innovation Solution
A display panel design featuring light emitting elements with a first and second light emitting layer stacked sequentially, where the first layer emits blue light and the second layer emits violet light, and an intermediate undoped layer, all using the same host material, with quantum dot blocks in subpixels converting the composite light into different colors, and optionally using a color filter or transparent insulating block in certain subpixels to enhance color output.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If quantum dots are used as color filters in conventional display panels, then color reproduction is achieved, but light conversion efficiency is low
Solution Approach 1:
The light emitting layer is divided into multiple sub-layers, each emitting at different wavelengths. This segmentation allows each layer to specialize in emitting specific colors, improving overall light conversion efficiency while maintaining color reproduction capability through the stacked configuration of first, second, and third light emitting layers
Solution Approach 2:
The patent uses composite light emitting layers with different host-guest material combinations to achieve both efficient light conversion and color reproduction. Each light emitting layer contains specific host materials and dopant materials that work together to emit at optimized wavelengths, resolving the contradiction between efficiency and color quality
2Manufacturing precision
If multiple light emitting layers are stacked to improve color accuracy, then color reproduction is enhanced, but device complexity increases
Solution Approach 1:
The intermediate layer serves multiple functions simultaneously: it acts as a buffer layer for mechanical stress relief, provides electrical isolation between layers, and facilitates optimal optical coupling. This multi-functionality reduces the need for additional separate layers, maintaining manufacturing precision while controlling device complexity
Solution Approach 2:
The patent optimizes specific parameters such as layer thickness (50-200 nm), doping concentrations, and material composition to achieve color accuracy improvements without proportionally increasing complexity. By carefully controlling these parameters, the system achieves enhanced color reproduction with minimal additional structural complexity
3Productivity
If ultraviolet light is emitted to improve excitation efficiency, then light conversion is enhanced, but harmful effects increase
Solution Approach 1:
The patent converts the potential harm of UV emission by using blue light emitting layers (450-480 nm) that provide sufficient excitation energy for quantum dots without emitting harmful ultraviolet wavelengths. The blue light serves as an effective pump source while avoiding the harmful effects of UV radiation, thus converting the energy requirement into a beneficial wavelength range
Solution Approach 2:
The light emitting layers are designed with specific local properties where the first light emitting layer emits blue light optimized for quantum dot excitation, while subsequent layers emit at different wavelengths. This local optimization ensures that excitation efficiency is maintained in the blue region without UV emission, while other regions handle color reproduction without contributing to harmful radiation
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 configuration enhances light conversion efficiency and color reproduction by emitting composite light that is effectively converted into specific colors in subpixels, improving the display panel's color accuracy and efficiency without ultraviolet light emission.
Implementation Method 1
the first light emitting layer is configured to emit a first light of a first wavelength range; the second light emitting layer is configured to emit a second light of a second wavelength range
Implementation Method 2
quantum dot blocks in subpixels converting the composite light into different colors
Data Source
AI summary
A light emitting element, includes a first light emitting layer and a second light emitting layer sequentially stacked; and an intermediate layer between the first light emitting layer and the second light emitting layer, and being in direct contact with the first light emitting layer on one side and in direct contact with the second light emitting layer on another side. Each of the intermediate layer, the first light emitting layer, and the second light emitting layer includes a same host material. The intermediate layer is a non-light emitting layer, and is an undoped layer absent of a dopant for emitting light. The light emitting element is configured to emit a composite light including the first light of the first wavelength range and the second light of the second wavelength range. The first wavelength range includes wavelength longer than the second wavelength range.