Reflective Layer in Pixel Definition Structure for OLED Light Efficiency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In OLED display apparatuses, the pixel definition layer absorbs light, leading to low light luminous efficiency, and transparent materials used to prevent this result in light leakage due to lateral emission of light.
Innovation Solution
A display substrate with a pixel definition structure that includes a reflective layer within subpixel apertures to reflect laterally emitted light back onto the light emitting surface, utilizing a base substrate with first and second pixel definition layers having different slope angles and optionally including insulating islands and truncated cones to optimize light reflection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the pixel definition layer is made of transparent materials to prevent light absorption, then light luminous efficiency is improved, but light leakage occurs due to lateral emission of light
Solution Approach 1:
The pixel definition layer is divided into multiple layers (first pixel definition layer and second pixel definition layer) with different functions. The first layer uses transparent materials to prevent light absorption, while the second layer incorporates a reflective layer to handle lateral light emission. This segmentation allows each layer to optimize for its specific function without compromising the other.
Solution Approach 2:
The harmful lateral emission of light is converted into a beneficial effect by introducing a reflective layer in the second pixel definition layer. This reflective layer redirects the laterally emitted light back toward the light emitting surface, transforming what was previously wasted light into useful illumination and improving overall light luminous efficiency.
2Object-generated harmful factors
If the pixel definition layer is made of opaque materials to prevent light leakage, then light leakage is reduced, but light luminous efficiency decreases due to light absorption
Solution Approach 1:
The pixel definition layer is segmented into two functional layers. The first layer uses transparent materials to maintain high light transmission, while the second layer introduces a reflective layer to prevent light leakage. This segmentation allows the system to achieve both goals without using opaque materials throughout.
Solution Approach 2:
The reflective layer acts as an intermediary between the light emitting element and the external environment. It intercepts laterally emitted light that would otherwise cause light leakage and redirects it back toward the light emitting surface, preventing harmful light leakage while preserving light luminous efficiency.
3Loss of energy
If a reflective layer is added to reflect laterally emitted light, then light luminous efficiency is improved, but device complexity increases
Solution Approach 1:
The reflective layer is merged with the second pixel definition layer, combining the structural function of pixel definition with the optical function of light reflection. This integration reduces the need for separate components and minimizes overall device complexity while achieving improved light luminous efficiency.
Solution Approach 2:
The second pixel definition layer serves multiple functions: it maintains the pixel definition structure and simultaneously incorporates the reflective layer to handle lateral light emission. This multi-functionality reduces the total number of components needed and simplifies the overall device architecture.
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 enhances light luminous efficiency by preventing light leakage and improving the reflection of laterally emitted light back onto the light emitting surface, thereby increasing the overall brightness and efficiency of the display.
Implementation Method 1
a reflective layer at least partially in a respective one of the plurality of first apertures and configured to reflect light laterally emitted from a respective one of the plurality of light emitting elements to exit from a light emitting surface
Data Source
AI summary
A display substrate is provided. The display substrate includes a base substrate; a pixel definition structure on the base substrate; a plurality of light emitting elements respectively in a plurality of first apertures; and a reflective layer at least partially in a respective one of the plurality of first apertures and configured to reflect light laterally emitted from a respective one of the plurality of light emitting elements to exit from a light emitting surface of the respective one of the plurality of light emitting elements. The pixel definition structure includes a first pixel definition layer on the base substrate, and a second pixel definition layer on a side of the first pixel definition layer away from the base substrate. Lateral sides of the first pixel definition layer and the second pixel definition layer have different slope angles with respect to a main surface of the base substrate.