OLED Anode Micro Cavity Resonance for Color Purity
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Solution Overview
Problem
OLED display elements have relatively low luminous intensity and efficiency due to their structural limitations.
Innovation Solution
Incorporating a micro cavity with an ITO layer and a metal oxide conductor layer as the anode, where the metal oxide conductor layer is positioned farther from the cathode than the ITO layer, allowing for improved work function and luminous intensity by adjusting the cavity length to enhance resonant cavity effects and narrow the light spectrum, thereby improving color purity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a conventional anode structure with only ITO layer is used, then the device structure is simple, but the luminous intensity and luminous efficiency are low
Solution Approach 1:
The anode is constructed using a composite structure combining ITO layer and metal oxide conductor layer, where each material contributes different properties. The ITO layer provides transparency and the metal oxide layer enhances work function, creating a composite anode that achieves higher luminous intensity while maintaining structural feasibility
Solution Approach 2:
The invention changes the work function parameter of the anode by introducing a metal oxide conductor layer with higher work function than ITO. This parameter change optimizes the energy level alignment between anode and organic light-emitting layer, improving hole injection efficiency and overall luminous efficiency
2Manufacturing precision
If the micro cavity length is not optimized, then the device structure is simple, but the color purity is low due to broad spectrum and color interference
Solution Approach 1:
The invention optimizes the cavity length parameter of the micro cavity to satisfy specific resonance conditions. By adjusting this geometric parameter, the device achieves narrow spectral width and improved color purity without requiring complex additional filtering structures
Solution Approach 2:
The micro cavity structure creates optical resonance effects where light waves undergo constructive and destructive interference based on cavity length. This resonance mechanism naturally filters the emission spectrum, narrowing the bandwidth and improving color purity through wave interference rather than physical filtering
3Use of energy by moving object
If the anode work function is not optimized, then the manufacturing process is simple, but the luminous efficiency is low
Solution Approach 1:
The invention systematically optimizes the work function parameter by selecting appropriate metal oxide materials and controlling their thickness. This parameter optimization ensures efficient charge injection and recombination in the organic light-emitting layer, directly improving luminous efficiency
Solution Approach 2:
The composite anode structure combines ITO and metal oxide layers to achieve synergistic effects. The ITO layer provides baseline transparency and conductivity while the metal oxide layer elevates the work function to optimal levels for efficient hole injection into the organic emitter
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 increases luminous intensity and efficiency while narrowing the light spectrum, preventing color interference and enhancing color purity of the OLED display element.
Implementation Method 1
The photons in various energy states are reallocated in the micro cavity between the anode and the cathode, so that the light beam transmitted from the organic light emitting layer and having a wavelength in conformity with a resonant cavity mode may be transmitted to an exterior of the OLED display element
Implementation Method 2
In the case that a voltage is applied to the OLED display element, holes in the ITO layer and the metal oxide conductor layer and electrons in the cathode are transported to the organic light-emitting layer. The holes and the electrons meet in the organic light-emitting layer, so as to excite the organic light-emitting layer to generate photons in various energy states, thereby to generate light beams
Data Source
AI summary
An OLED display element, its manufacturing method and a display device are provided. The OLED display element includes a light-emitting pixel unit. The light-emitting unit includes an anode arranged above a base substrate, a cathode arranged opposite to the anode, and a micro cavity formed between the anode and the cathode. The micro cavity includes an organic light-emitting layer, and the anode includes an ITO layer arranged opposite to the cathode and a metal oxide conductor layer arranged at a side of the ITO layer that is farther away from the cathode than the other side of the ITO layer.