Curved Light-Adjusting Layer for OLED Viewing Angle
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Solution Overview
Problem
Conventional top-emission type OLED devices have a narrow viewing angle due to optical path differences and microcavity effects, leading to varying light spectra and intensities at different observation points.
Innovation Solution
A display substrate with a light-adjusting layer having a curved surface towards the base substrate, a carrier-balancing layer, and a pixel defining layer, which adjusts light emission and balances carrier injection rates to improve luminous efficiency and viewing angle.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a conventional top-emission type OLED device is used, then the aperture ratio is high, but the viewing angle is narrow due to optical path differences and microcavity effects
Solution Approach 1:
The patent introduces a light-adjusting layer with a curved surface (concave toward the anode) to replace the conventional flat structure. This curvature modifies the optical path of emitted light, enabling light from different positions in the organic functional layer to reach the observation point with more uniform paths, thereby expanding the viewing angle while maintaining aperture ratio
Solution Approach 2:
The light-adjusting layer serves as an intermediary component between the organic functional layer and the observation space. It mediates the optical interaction by adjusting the light paths through its curved surface, resolving the microcavity effect and optical path differences without requiring fundamental changes to the OLED structure
2Illumination intensity
If a light-adjusting layer with curved surface is added, then the viewing angle and light extraction efficiency are improved, but the device structure becomes more complex
Solution Approach 1:
The light-adjusting layer performs multiple functions simultaneously: it adjusts optical paths to improve viewing angle, enhances light extraction efficiency through its curved surface, and can be integrated with existing OLED layers without requiring complete structural redesign. This multi-functionality justifies the added structural complexity
3Stability of the object's composition
If the light-adjusting layer is positioned between the organic functional layer and the base substrate, then the microcavity effect is minimized, but the manufacturing process becomes more difficult
Solution Approach 1:
The light-adjusting layer is formed prior to depositing the organic functional layer, establishing the optimized optical path structure before subsequent layers are added. This preliminary action ensures the curved surface geometry is preserved and the microcavity effect is minimized from the outset of device operation
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 solution enhances the viewing angle and luminous efficiency of OLED devices by reflecting light emitted by the light-emitting layer and balancing carrier injection rates, minimizing the microcavity effect and improving light extraction efficiency.
Implementation Method 1
a light-adjusting layer between the light-emitting layer and the base substrate and configured to adjust light emitted by the light-emitting layer
Implementation Method 2
a surface of the light-adjusting layer closer to the light-emitting layer is a curved surface that recesses toward the base substrate
Implementation Method 3
a carrier-balancing layer between the light-adjusting layer and the light-emitting layer and configured to balance an injection rate of carriers of the first electrode
Data Source
AI summary
The present disclosure provides a display substrate, a display device and a method of fabricating the display substrate. The display substrate comprises: a base substrate; a light-emitting layer on the base substrate; and a light-adjusting layer between the light-emitting layer and the base substrate to adjust light emitted by the light-emitting layer.