OLED Pixel Definition Layer Structure for Leakage and Reflection Control
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Solution Overview
Problem
OLED display panels suffer from issues such as lateral leakage currents leading to crosstalk and reduced contrast due to lateral migration of carriers through common layers, and reflectivity due to ambient light reflection from metal structures.
Innovation Solution
The display panel design incorporates multiple pixel definition layers with light-shielding materials and strategically designed openings to prolong the path of leakage currents and reduce ambient light reflection, using a three-layer pixel definition structure that includes a third pixel definition layer to isolate common layers from driving function layers and prevent contact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single pixel definition layer is used, then the device complexity is low, but lateral leakage currents cause crosstalk and reduced contrast
Solution Approach 1:
The pixel definition layer is divided into three separate layers (first, second, and third pixel definition layers) stacked at different positions. Each layer contains openings that collectively form a multi-level aperture structure, segmenting the light transmission path and preventing lateral leakage currents from causing crosstalk between adjacent pixels, thereby improving contrast ratio.
Solution Approach 2:
The patent transitions from a two-dimensional single-layer pixel definition structure to a three-dimensional multi-layer stacked structure. The first and second pixel definition layers are positioned at different heights (Z-axis), creating a vertical aperture arrangement that blocks lateral carrier migration paths while maintaining light transmission, thus resolving the crosstalk issue without excessive complexity.
2Reliability
If metal structures are used in the display panel, then electrical conductivity and device performance are improved, but ambient light reflection increases
Solution Approach 1:
The patent applies different surface treatments or materials to specific regions of the metal structures. The pixel definition layers incorporate openings and aperture structures at localized positions where light reflection is problematic, while maintaining the metal structures' electrical conductivity in other regions. This selective approach reduces ambient light reflection without compromising overall electrical performance.
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 design effectively suppresses lateral leakage currents, improves contrast ratio, and reduces reflectivity by extending the path of leakage currents and absorbing ambient light, thereby enhancing display performance.
Implementation Method 1
At least one of the first pixel definition layer and the second pixel definition layer includes a light-shielding material
Data Source
AI summary
A display panel, a method for preparing the display panel and a display apparatus are provided. The display panel includes a first pixel definition layer including a first pixel opening and a first opening, a second pixel definition layer including a second pixel opening and a second opening, and a third pixel definition layer. The first opening penetrates the first pixel definition layer, and at least partially surrounds the first pixel opening. The second opening penetrates the second pixel definition layer, and at least partially surrounds the second pixel opening. Along a direction perpendicular to a plane of the substrate, the second opening at least partially overlaps the first opening. The third pixel definition layer at least partially overlaps the first opening. At least one of first pixel definition layer and second pixel definition layer includes a light-shielding material.