Quantum Dot Display Electrode Structure for Uniform Light Emission
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Solution Overview
Problem
Display devices using quantum dots face challenges in achieving uniform light emitting intensity across pixels due to variations in film thickness of the light emitting layer, leading to issues with light leakage and accurate color display, especially in high-definition panels with micro-pixels.
Innovation Solution
A light emitting device structure is implemented with a quantum dot light emitting layer sandwiched between a first electrode and a second electrode, where the second electrode is positioned to overlap the first electrode only partially, and an insulation layer is used to control the electric field intensity, reducing the impact of film thickness variations and preventing light leakage between pixels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the light emitting layer film thickness is varied, then the manufacturing process is simpler, but the light emitting intensity becomes non-uniform across pixels
Solution Approach 1:
The patent introduces an insulation layer as an intermediary between the first electrode and the light emitting layer. This insulation layer mediates the electric field distribution, ensuring uniform light emission even when the light emitting layer thickness varies. The insulation layer acts as a buffer that decouples the direct relationship between electrode proximity and light emission intensity.
Solution Approach 2:
The patent changes the electrical parameters by introducing the insulation layer with specific dielectric properties. This alters the electric field distribution pattern, transforming it from a direct inverse-square law relationship to a more uniform distribution that is less sensitive to light emitting layer thickness variations.
2Power
If the second electrode is positioned closer to the light emitting layer, then the light emitting efficiency increases, but light leakage between pixels occurs
Solution Approach 1:
The patent segments the electrode structure by introducing the insulation layer between the first electrode and the light emitting layer. This segmentation allows the second electrode to be positioned close to the light emitting layer for high efficiency while the insulation layer prevents lateral electric field extension that would cause light leakage into adjacent pixels.
Solution Approach 2:
The insulation layer serves as a mediator that enables close positioning of the second electrode to the light emitting layer while preventing harmful lateral field extension. It transmits the necessary vertical electric field for efficient light emission while blocking the horizontal field components that would cause pixel crosstalk.
3Device complexity
If the electrode structure is simplified, then the device complexity decreases, but the control over electric field intensity becomes insufficient
Solution Approach 1:
The insulation layer acts as a controllable intermediary that provides precise electric field intensity control without requiring complex electrode geometries. By adjusting the insulation layer thickness and dielectric constant, the electric field intensity can be precisely controlled while maintaining a simple planar electrode structure.
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 ensures consistent light emitting intensity across pixels, prevents light leakage, and enhances color accuracy by controlling the electric field distribution and light extraction efficiency, even in high-resolution displays.
Implementation Method 1
a quantum dot can adjust a light emitting wavelength by changing the size of a particle, and includes the advantages of high light emitting efficiency and no concentration quenching which could not be obtained in conventional materials
Implementation Method 2
These nanoparticles emit light when irradiated with an external energy beam (ultraviolet light or blue light etc.) or by applying and electrical field
Implementation Method 3
an insulation layer is used to control the electric field intensity, reducing the impact of film thickness variations
Data Source
AI summary
A display device includes a pixel part provided with a plurality of pixels, and a light emitting device provided in the pixel, wherein the light emitting device includes a light emitting layer including a quantum dot, a first electrode provided on one surface of the light emitting layer, an insulation layer provided between the light emitting layer and the first electrode, and a second electrode provided between the light emitting layer and the insulation layer, and at least one end part of the second electrode layer is provided over the first electrode.