OLED Display Substrate with Heat-Generated Carrier Cutoff
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Solution Overview
Problem
Current OLED display substrates face current crosstalk issues due to the whole layer structure of the hole transport layer, which affects the display effect by allowing holes to move between different pixel regions, leading to reduced display color purity.
Innovation Solution
A manufacturing method for a display substrate involving a pixel defining layer doped with a heat-generating material, where a first carrier transport layer and a second carrier transport layer are formed with an overlapping region, and the heat-generating material generates heat to mix the materials of these layers, creating a carrier cutoff region that disrupts hole transmission paths between pixel regions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the hole transport layer is designed as a whole layer structure, then the manufacturing process is simple, but holes can move between pixel regions causing current crosstalk
Solution Approach 1:
The hole transport layer is segmented into multiple regions: a first hole transport layer in the display region, a second hole transport layer in the non-display region, and an overlapping region where materials mix to form a carrier cutoff region. This segmentation prevents holes from moving between pixel regions while maintaining manufacturing feasibility through sequential deposition processes.
Solution Approach 2:
Different regions of the hole transport layer are assigned different material compositions and functions. The overlapping region contains a mixed material with different hole mobility characteristics compared to the display region, creating local quality variations that block current crosstalk while preserving normal hole transport in the display area.
2Reliability
If the hole transport layer is segmented to prevent current crosstalk, then current crosstalk is reduced, but the device structure becomes more complex
Solution Approach 1:
The first hole transport layer, second hole transport layer, and intermediate layer are merged in the overlapping region to form a mixed material layer. This merging creates the carrier cutoff region that prevents current crosstalk while integrating multiple functions into a single structural element, reducing overall device complexity.
Solution Approach 2:
An intermediate layer is introduced as a mediator between the first and second hole transport layers. This intermediate layer facilitates the mixing of materials in the overlapping region to form the carrier cutoff region, enabling current crosstalk prevention while maintaining a manageable layer structure.
3Reliability
If heat-generating material is doped in the pixel defining layer, then the carrier cutoff region is formed effectively, but the manufacturing process becomes more complex
Solution Approach 1:
The pixel defining layer is doped with heat-generating material (such as gold or palladium particles) that changes the thermal properties of the layer. When infrared light is applied, the doped material generates heat locally in the overlapping region, causing the organic materials to mix and form the carrier cutoff region. This parameter change enables precise control over where the cutoff region forms.
Solution Approach 2:
The mechanical process of forming the carrier cutoff region through physical mixing is replaced by a thermal field approach. Infrared light heating the doped pixel defining layer creates localized temperature increases that drive material mixing, substituting mechanical intervention with a field-based process that is easier to control and integrate into existing manufacturing lines.
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 reduces the probability of current crosstalk between pixel regions, ensuring improved display effects by maintaining the integrity of the display substrate's color purity and reducing hole transmission between adjacent regions.
Implementation Method 1
the heat-generating material is a light absorbing material, and the specified condition is to irradiate the light absorbing material with infrared light
Implementation Method 2
the light absorbing material comprises vanadium pentoxide, titanium dioxide, tellurium dioxide or bismuth oxide
Implementation Method 3
controlling the heat-generating material to generate heat under the specified condition, and allowing a material of the first carrier transport layer to mix with a material of the second carrier transport layer in the overlapping region
Data Source
AI summary
A display substrate, a manufacturing method thereof and a display device are disclosed. The method includes: forming a pixel defining layer being doped with a heat-generating material capable of generating heat under specified conditions; sequentially forming a first carrier transport layer, a light-emitting material layer and a second carrier transport layer, wherein orthographic projections of the first and second carrier transport layers and the pixel defining layer on the base substrate have an overlapping region; controlling the heat-generating material to generate heat under specified conditions, and allowing a material of the first carrier transport layer to mix with a material of the second carrier transport layer in the overlapping region.