OLED First Electrode Thickness Variation for Viewing Angle
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Solution Overview
Problem
Organic light emitting display devices with white OLEDs suffer from deteriorated viewing angle and efficiency due to varying luminescence characteristics across different wavelengths, which affect their performance in terms of color reproduction and luminous efficiency.
Innovation Solution
The method involves forming first electrodes for red, green, blue, and white sub-pixels with specific thickness variations, using multiple transparent conductive layers, and arranging them in a manner that the red and blue sub-pixels have a greater thickness than the green and white sub-pixels, with the white organic common layer comprising multiple light emitting units and charge generation layers to enhance luminous efficiency and color viewing angle.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If white OLEDs use a single thickness first electrode, then manufacturing is simple, but luminous efficiency and color viewing angle are deteriorated
Solution Approach 1:
The patent applies local quality by forming first electrodes with different thicknesses for different sub-pixels (red, green, blue, white). Specifically, red and blue sub-pixels have a first electrode thickness of 1100-1500 Å, while green and white sub-pixels have a thickness of 600-1200 Å. This localized variation in electrode thickness optimizes luminous efficiency and color viewing angle for each sub-pixel type, resolving the contradiction between manufacturing simplicity and performance reliability.
2Device complexity
If white OLEDs use uniform electrode structure, then device complexity is low, but performance in color reproduction and luminous efficiency is poor
Solution Approach 1:
The patent implements local quality through differentiated first electrode structures for different sub-pixels. The red and blue sub-pixels utilize thicker first electrodes (1100-1500 Å) compared to green and white sub-pixels (600-1200 Å). This localized structural variation enhances color reproduction accuracy and luminous efficiency for each sub-pixel type while maintaining overall device functionality, effectively balancing structure complexity with performance reliability.
Data Source
AI summary
An organic light emitting display device with enhanced luminous efficiency and color viewing angle and a method of manufacturing the same are disclosed. The method includes forming a first electrode of each of red, green, blue and white sub-pixels on a substrate, forming a white organic common layer on the first electrodes, and forming a second electrode on the white organic common layer, wherein the first electrodes each includes multiple transparent conductive layers and is formed such that a thickness of the first electrode of each of two sub-pixels among the red, green, blue and white sub-pixels is greater than a thickness of the first electrode of each of the other two sub-pixels, and at least two layers excluding the lowermost layer among the multiple transparent conductive layers of each first electrode are formed to cover opposite sides of the lowermost layer.