Stacked Microdisplay Pixel Unit for Low-Efficiency Micro-LEDs
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional Micro-LEDs experience a significant decrease in external quantum efficiency when their size is reduced to 20 μm or lower, leading to increased power consumption and performance issues, particularly with red-emitting LEDs based on the AlGaInP system.
Innovation Solution
A pixel unit is designed with a backplane and a display unit, where the display unit consists of vertically stacked first and second device layers. The first device layer includes adjacent first and second compound light-emitting layers, while the second device layer includes a color conversion layer and a third compound light-emitting layer, with the color conversion layer positioned above the first compound light-emitting layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of moving object
If the LED size is reduced to 20 μm or lower for display purposes, then the pixel density and display resolution are improved, but the external quantum efficiency decreases significantly leading to increased power consumption and performance degradation
Solution Approach 1:
The patent transitions from horizontal arrangement of multiple LEDs to vertical stacking of compound light-emitting layers. By stacking first and second compound light-emitting layers vertically, the device achieves multi-color emission within a compact footprint, effectively utilizing the vertical dimension to maintain high pixel density while preserving the external quantum efficiency of individual micro-LEDs at 20 μm or smaller sizes.
2Ease of manufacture
If conventional LEDs are directly used as display pixels at micrometer scale, then the manufacturing process is simple, but the yield loss is significant and cannot be ignored
Solution Approach 1:
The patent segments the light-emitting function into multiple compound light-emitting layers with different emission characteristics. Each layer can be independently optimized and manufactured, allowing defective layers to be replaced or compensated without scrapping the entire device. This segmentation approach maintains manufacturing simplicity while significantly improving yield by enabling modular repair and compensation strategies.
3Area of moving object
If the LED size is reduced to increase pixel density, then the display resolution is improved, but optical crosstalk between adjacent pixels increases
Solution Approach 1:
By stacking compound light-emitting layers vertically, the patent confines light emission to specific vertical zones. Each compound light-emitting layer emits light in a controlled direction, and the vertical separation between layers reduces lateral light spread. This dimensional transition effectively isolates adjacent pixels both horizontally and vertically, minimizing optical crosstalk while maintaining high pixel density.
4Adaptability or versatility
If red-emitting LEDs based on AlGaInP system are used at micrometer scale, then the display coverage is improved, but the external quantum efficiency decreases greatly affecting brightness
Solution Approach 1:
The patent merges multiple compound light-emitting layers with different emission characteristics to achieve full-color display. By combining the emission from first and second compound light-emitting layers, the device achieves broad color coverage while each individual layer operates at optimal efficiency. This merging approach allows red, green, and blue emissions to be combined without requiring each micro-LED to achieve high efficiency at all wavelengths, thereby maintaining brightness while improving color coverage.
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 effectively reduces the impact of size effects on external quantum efficiency, improves brightness and power efficiency, and enhances yield by enabling multi-color display with reduced horizontal space occupation and minimized optical crosstalk.
Implementation Method 1
the second device layer includes a color conversion layer and a third compound light-emitting layer adjacent to each other, and the color conversion layer is arranged above the first compound light-emitting layer
Data Source
AI summary
This application provides a pixel unit, a manufacturing method therefor, a microdisplay, and a pixel-level discrete device. The pixel unit includes a backplane and a display unit. The display unit is arranged on the backplane, and includes a first device layer and a second device layer. The first device layer includes a first compound light-emitting layer and a second compound light-emitting layer. The second device layer includes a color conversion layer and a third compound light-emitting layer. The color conversion layer is arranged above the first compound light-emitting layer. The color conversion layer is arranged, so that the compound light-emitting layer can implement color development through color conversion, to reduce power and improve performance. The pixel unit occupies less space in the horizontal direction. A decrease in external quantum efficiency caused by a size effect is effectively reduced, power consumption is effectively reduced, and performance such as brightness is improved.