OLED Sub-pixel Optical Path Adjustment for Color Stability
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Solution Overview
Problem
Organic electroluminescent devices face challenges in achieving high light extraction efficiency and color accuracy due to differences in aging rates of RGB materials, leading to color deterioration and reduced color range in full-color displays.
Innovation Solution
An organic light-emitting device with a substrate and a pixel array comprising sub-pixels with optical path adjustment layers, where each sub-pixel has a color light-emitting layer positioned at an antinode of a standing wave, and all layers are formed using the same materials and processes, enhancing luminous efficiency and simplifying manufacturing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If white OLED with RGB color filters is used to achieve full-color display, then color conversion is possible, but spectral mismatch enlarges FWHM and reduces color saturation (NTSC ratio)
Solution Approach 1:
The device divides the display into separate red, green, and blue sub-pixels, each with its own organic electroluminescent layer emitting specific wavelengths. This segmentation eliminates the need for color filters and maintains narrow FWHM for each color, preserving color saturation while achieving full-color display capability.
Solution Approach 2:
Each sub-pixel is designed with specific organic electroluminescent materials tailored to emit precise wavelengths (red: 610-650nm, green: 520-560nm, blue: 460-500nm). This local optimization of material properties ensures each pixel emits light with narrow spectral width, maintaining high color saturation without requiring color filters.
2Adaptability or versatility
If RGB pixels side-by-side configuration is used to form full-color display, then red, green and blue color pixels can be formed, but individual aging rates of RGB organic electroluminescent materials are different leading to color deterioration over time
Solution Approach 1:
The device optimizes the thickness of optical path adjustment layers in each sub-pixel to compensate for different aging rates of RGB materials. By adjusting the optical path length parameter (thickness) of each sub-pixel, the invention balances the luminous intensity decay of different colors over time, maintaining color accuracy and reducing color deterioration despite material aging differences.
3Reliability
If optical path adjustment layers with different thicknesses are used for different sub-pixels to compensate for aging, then color accuracy can be maintained, but manufacturing complexity increases
Solution Approach 1:
The optical path adjustment layer serves multiple functions: it compensates for aging effects, adjusts optical path length, and maintains color accuracy. By designing a unified layer structure that performs multiple functions, the invention reduces overall device complexity while achieving color stability without requiring separate compensation mechanisms for each sub-pixel.
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 improves light extraction efficiency and maintains color accuracy by positioning light-emitting layers at antinodes within sub-pixels, reducing manufacturing complexity and extending the lifespan of full-color displays.
Implementation Method 1
each sub-pixel has a color light-emitting layer positioned at an antinode of a standing wave
Data Source
AI summary
The disclosure provides an organic light-emitting device. The organic light-emitting device includes a substrate, and an organic light-emitting pixel array disposed on the substrate. The organic light-emitting pixel array includes a plurality of pixels. Each pixel includes a first sub-pixel and a second sub-pixel. Each sub-pixel includes a first electrode, an organic light-emitting element, a second electrode, and an optical path adjustment layer. The optical path adjustment layer is disposed between the first electrode and the second electrode. Particularly, the thickness of the optical path adjustment layer of the first sub-pixel is substantially equal to the thickness of the optical path adjustment layer of the second sub-pixel.