Island-Shaped EL Layers With Sidewall Insulators
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Solution Overview
Problem
Current display devices face challenges in achieving high-resolution, high-definition, and highly reliable performance, particularly in reducing leakage current and crosstalk between subpixels, which affects display quality and aperture ratio.
Innovation Solution
The display device incorporates island-shaped electroluminescent (EL) layers with sidewall insulating layers to prevent short circuits and crosstalk, using a method that does not require a fine metal mask, allowing for closer pixel spacing and higher aperture ratios, and employs a structure where the EL layer is locally thinned or separated between light-emitting devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional display devices are used, then manufacturing is simpler, but resolution and definition are insufficient
Solution Approach 1:
The patent divides the light-emitting structure into separate islands for each subpixel, with insulating layers between them. This segmentation prevents crosstalk while maintaining high resolution, as each light-emitting region is electrically isolated yet closely spaced.
Solution Approach 2:
The patent introduces insulating layers as intermediary structures between adjacent light-emitting devices. These insulating layers act as mediators that prevent electrical crosstalk and short circuits while allowing the pixels to be positioned closely together for high resolution.
2Manufacturing precision
If pixel spacing is reduced for higher resolution, then aperture ratio increases, but leakage current and crosstalk increase
Solution Approach 1:
The light-emitting layer is segmented into isolated islands for each subpixel, preventing electrical leakage between adjacent pixels. This allows reduced pixel spacing without increasing crosstalk, as each island is electrically independent.
Solution Approach 2:
Insulating layers are positioned between adjacent light-emitting devices as intermediary barriers. These layers prevent charge carrier leakage and crosstalk while allowing the pixels to be closely spaced for high resolution and aperture ratio.
3Reliability
If insulating layers are added to prevent crosstalk, then reliability improves, but manufacturing complexity increases
Solution Approach 1:
The patent combines multiple functions into the insulating layers: they serve as both electrical isolation barriers to prevent crosstalk and as structural elements that define the island shapes of the light-emitting regions. This merging reduces the need for separate isolation structures.
Solution Approach 2:
The insulating layers perform multiple functions simultaneously: electrical isolation, structural definition of pixel boundaries, and support for the light-emitting layer. This multi-functionality reduces overall device complexity despite adding reliability features.
4Reliability
If EL layer is separated into islands, then crosstalk is reduced, but manufacturing precision requirements increase
Solution Approach 1:
The insulating layers are formed first to create self-aligned regions that guide the subsequent formation of light-emitting material islands. The pre-formed insulating structure serves as a template, reducing the precision requirements for island formation compared to direct patterning.
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 approach enables high-resolution and high-definition displays with improved reliability, reduced leakage current, and increased aperture ratio, leading to enhanced display quality and increased yield in manufacturing.
Implementation Method 1
island-shaped electroluminescent (EL) layers
Data Source
AI summary
A high-resolution display device is provided. A first light-emitting device and a second light-emitting device are included over an insulating surface. A first sidewall insulating layer is in contact with a side surface of a first pixel electrode included in the first light-emitting device, and a second sidewall insulating layer is in contact with a side surface of a second pixel electrode included in the second light-emitting device. The first light-emitting device overlaps with a first coloring layer, and the second light-emitting device overlaps with a second coloring layer that transmits light of a color different from a color of light transmitted through the first coloring layer. The first light-emitting device and the second light-emitting device share a common electrode. A first layer included in the first light-emitting device, a second layer included in the second light-emitting device, and a material layer positioned over the top surface of an insulating layer and positioned between the first sidewall insulating layer and the second sidewall insulating layer contain the same light-emitting material and are apart from one another.