Multi-Color Electroluminescent Display Pixels via Nano-Opening Epitaxy
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for forming multi-color light-emitting display devices face challenges such as difficulty in bonding and aligning pixels on a substrate with small pitch, limited lifetime of materials, and high cost due to multiple epitaxy sequences for achieving different emission wavelengths.
Innovation Solution
A light-emitting device comprising multiple cells with stacks of semiconductor materials, where each cell has a specific layer structure and nano-openings in a mask to form interfaces between layers, allowing for simultaneous epitaxy of cells emitting in different wavelength ranges, reducing the need for multiple epitaxy sequences and color conversion elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If pixels are transferred onto a same substrate based on different semiconductor materials, then multi-color emission is achieved, but bonding and alignment difficulty increases
Solution Approach 1:
The patent merges the formation of different semiconductor layers (GaN and AlGaN) into a single epitaxial growth process on a common substrate. By using a mask with through-openings to define pixel regions and controlling indium incorporation during a single epitaxy sequence, the invention simultaneously forms multiple light-emitting cell types without requiring separate transfer and bonding steps, thus resolving the manufacturing complexity while maintaining multi-color capability
Solution Approach 2:
The patent segments the substrate into different pixel regions using a mask with through-openings, where each region is selectively exposed to indium-containing precursors during epitaxy. This spatial segmentation allows different semiconductor compositions to be formed in different pixel areas during a single growth process, enabling multi-color emission without complex bonding operations
2Adaptability or versatility
If color conversion layers are deposited locally to achieve different wavelengths, then multi-color display is enabled, but local deposition difficulty and material lifetime limitations increase
Solution Approach 1:
Instead of converting a single wavelength to multiple wavelengths using color conversion layers deposited after epitaxy, the patent inverts the approach by directly forming multiple wavelength-emitting semiconductor structures during the epitaxial growth process itself. By controlling indium incorporation in different pixel regions, the invention achieves multi-color emission from the light-emitting cells themselves, eliminating the need for subsequent color conversion layer deposition and associated manufacturing difficulties
3Adaptability or versatility
If multiple successive epitaxy sequences are used to form different light-emitting cells, then wavelength diversity is achieved, but manufacturing cost increases
Solution Approach 1:
The patent combines the formation of multiple light-emitting cell types with different emission wavelengths into a single epitaxial growth sequence. By using a mask to define pixel regions and controlling indium precursor incorporation during this unified process, the invention simultaneously forms GaN-based and AlGaN-based light-emitting cells with different bandgaps and emission wavelengths, reducing manufacturing complexity and cost compared to multiple separate epitaxy sequences
4Measurement precision
If small pitch between pixels is implemented, then display resolution is improved, but pixel transfer and alignment precision requirements increase
Solution Approach 1:
The patent segments the substrate into densely packed pixel regions defined by a mask with through-openings, allowing direct in-situ formation of multiple pixel types during a single epitaxial growth process. This approach eliminates the need for post-growth transfer and alignment operations, enabling small pitch implementations without the associated precision alignment challenges
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
Enables the efficient formation of multi-color display devices with reduced complexity and cost, while achieving desired emission wavelengths through strain-induced indium concentration differences in the active layers.
Implementation Method 1
achieving desired emission wavelengths through strain-induced indium concentration differences in the active layers
Data Source
AI summary
A device including first and second light-emitting cells respectively emitting in first and second wavelength ranges, wherein:each cell includes a stack of a first layer of a first semiconductor material and of a second layer of a second semiconductor material having a different mesh parameter;in the first cell, the first layer is in contact with the second layer across the entire surface of the cell; andin the second cell, a mask provided with a plurality of through nano-openings forms an interface between the first layer and the second layer, the second layer comprising a plurality of nanopillars of the second material arranged in the nano-openings of the mask, and a coalesced layer extending across substantially the entire surface of the cell on the side of the mask opposite to the first layer.