OLED Capping Layer Thickness for Light Transmittance
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Solution Overview
Problem
Transparent organic light-emitting display (OLED) devices face challenges in optimizing optical characteristics, such as transmittance, due to the complexity of component variables like composition, disposition, and thickness of layers like substrates, electrodes, and insulation layers.
Innovation Solution
The OLED device is designed with distinct regions for emission and transmission, featuring pixel electrodes, light-emitting layers, and common electrodes with varying thicknesses in capping and common electrodes to enhance light transmittance and efficiency, allowing for top and dual emission capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If multiple insulation layers with different materials are stacked in the OLED device, then the device structure is completed with necessary functional layers, but the optical characteristics (transmittance) of the OLED device deteriorate
Solution Approach 1:
The patent applies local quality by making the capping layer thickness non-uniform across different regions. Specifically, the capping layer has a first thickness in the first emission region, a second thickness in the second emission region, and a third thickness in the transmission region, where these thicknesses differ. This localized variation in thickness optimizes light transmittance in the transmission region while maintaining device functionality, directly resolving the contradiction between completing the device structure and improving optical characteristics.
2Ease of manufacture
If the capping layer has uniform thickness across all regions, then the manufacturing process is simplified, but the light transmittance in transmission regions cannot be optimized
Solution Approach 1:
The patent implements local quality by specifying that the capping layer has different thicknesses in different regions: a first thickness in the first emission region, a second thickness in the second emission region, and a third thickness in the transmission region. This regional differentiation allows optimization of light transmittance in the transmission region without compromising the overall device structure or manufacturing feasibility.
3Adaptability or versatility
If the OLED device is designed for dual emission (top and bottom), then the device functionality is enhanced, but the structural complexity increases making optimization of various component variables more difficult
Solution Approach 1:
The patent resolves the complexity issue by applying local quality principles to the capping layer thickness distribution. By defining specific thickness regions (first thickness in first emission region, second thickness in second emission region, third thickness in transmission region), the patent simplifies the optimization process while maintaining dual emission functionality. This regional approach allows independent optimization of each region's characteristics without requiring complex global adjustments.
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 improves light transmittance in transmission regions and enhances light-emitting efficiency, enabling better image quality and user experience by optimizing the structure of the OLED device.
Implementation Method 1
a first pixel electrode disposed in the first emission region, the first pixel electrode configured to reflect light
Implementation Method 2
a second pixel electrode disposed in the second emission region, the second pixel electrode configured to transmit light
Implementation Method 3
a light emitting layer disposed on the first pixel electrode and the second pixel electrode
Data Source
AI summary
An OLED device including a first emission region, a second emission region, and a transmission region, a pixel circuit disposed on a substrate, a first pixel electrode reflecting light disposed in the first emission region, a second pixel electrode transmitting light disposed in the second emission region, a light emitting layer disposed on the first and second pixel electrodes, a common electrode transmitting light disposed on the light emitting layer and including first, second, and third common electrodes respectively overlapping the first emission region, the second emission region, and the transmission region, and a capping layer disposed on the common electrode and including first, second, and third capping layers respectively overlapping the first emission region, the second emission region, and the transmission region, in which at least two of the first capping layer, the second capping layer, and the third capping layer have different thicknesses from each other.