Micro LED Pixel Structure with Reflective Metal Nanoparticle Layer
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Solution Overview
Problem
Micro LED displays suffer from low light energy utilization due to the uniform illumination of independent light-emitting units, leading to significant light loss in existing pixel structures.
Innovation Solution
A pixel structure is developed with a substrate, a black photoresist layer having a receiving cavity and isolation region, a polyelectrolyte layer, and a metal nanoparticle layer, where the micro light-emitting diode is positioned on the isolation region, utilizing materials like Au, Ag, Cu, Ni, Co, or their alloys, and specific polyelectrolytes such as Poly Diallyl Dimethyl Ammonium Chloride, to form a reflective layer enhancing light utilization efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a conventional pixel structure with cavity walls formed by black photo resist and LED disposed in cavity is used, then the structure is simple to manufacture, but the light utilization efficiency is low due to uniform illumination in all directions causing light loss
Solution Approach 1:
The patent applies local quality by creating a reflective layer at the bottom of the receiving cavity using metal nanoparticles. This localized reflective structure redirects light that would otherwise be lost, converting it toward the observation direction. The reflective layer is selectively positioned only where needed to improve light extraction without complicating the overall manufacturing process.
Solution Approach 2:
The patent converts the harmful effect of light loss into a beneficial outcome by introducing a reflective layer that captures light escaping in non-observation directions and redirects it toward the observation direction. This transforms wasted light energy into useful light output, improving overall light utilization efficiency without requiring fundamental changes to the LED structure.
2Loss of energy
If a reflective metal layer is added to improve light utilization efficiency, then light energy loss is reduced, but the device complexity increases
Solution Approach 1:
The patent changes the physical and chemical parameters of the reflective layer by using metal nanoparticles with specific sizes (20-200 nm) and controlling their distribution through polyelectrolyte coating. This nanoparticle-based approach creates an effective reflective layer with optimized optical properties while maintaining a relatively simple manufacturing process through conventional deposition techniques.
Solution Approach 2:
The patent employs composite materials by combining metal nanoparticles with polyelectrolyte layers to form a functional reflective structure. The polyelectrolyte serves as a binding matrix that holds the metal nanoparticles in place, creating a composite material that provides both structural stability and optical reflectivity without requiring complex fabrication processes.
3Loss of energy
If metal nanoparticle layer with polyelectrolyte is used to form reflective layer, then light utilization efficiency is improved through increased reflectance, but the manufacturing precision requirements increase
Solution Approach 1:
The patent applies self-service through the self-assembly behavior of metal nanoparticles on the polyelectrolyte-coated substrate. The nanoparticles naturally organize themselves into a distributed reflective layer through electrostatic interactions with the polyelectrolyte, reducing the need for precise external control during manufacturing. This self-organizing mechanism simplifies the fabrication process while achieving the desired reflective properties.
Solution Approach 2:
The patent uses a relatively high concentration of metal nanoparticles (0.1-10 mg/mL) to ensure sufficient coverage and reflectivity. By applying an excessive amount of nanoparticles, the patent ensures that even with variations in deposition conditions, the reflective layer achieves the necessary optical performance, thereby reducing the stringency of manufacturing precision requirements.
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 proposed structure improves light utilization efficiency by reducing light loss through the use of a reflective metal nanoparticle layer, which converges emitted light and increases reflectance, thereby enhancing the overall light utilization rate of micro light-emitting diodes.
Implementation Method 1
the metal nanoparticle layer is covered on the polyelectrolyte layer... the metal nanoparticle layer, which converges emitted light and increases reflectance
Implementation Method 2
a polyelectrolyte layer, the polyelectrolyte layer is coated on the black photoresist layer expect the isolation region; a metal nanoparticle layer, the metal nanoparticle layer is covered on the polyelectrolyte layer
Data Source
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AI summary
Disclosed are a pixel structure and a manufacturing method. The manufacturing method comprises: preparing a substrate (11); manufacturing, on the substrate, a black photoresist layer (12) with an accommodation cavity (121) and an isolation area (122); coating a surface, other than the isolation area, of the black photoresist layer with a polyelectrolyte solution, air-drying the surface, and forming a polyelectrolyte layer (13); coating a surface of the polyelectrolyte layer with a metal nano-particle solution, air-drying the surface, and forming a metal particle layer (14); and aligning and transferring a micro lightemitting diode (15) to the black photoresist layer. By means of the method, the light utilization rate of a micro light-emitting diode can be increased.