Phase Change Material Layer for Multi-Color OLED Lighting
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Solution Overview
Problem
Conventional organic light emitting diode (OLED) lighting devices are limited to single color illumination due to surface emission, restricting the implementation of various patterns and colors.
Innovation Solution
Incorporating a phase change material layer between the organic light emitting layer and the substrate, with strategically positioned third electrodes, allows for the transformation of light color based on the phase change state, enabling the creation of patterns with multiple colors and shapes at low power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a phase change material layer and third electrodes are added to enable multiple colors and patterns, then color variety and pattern implementation are improved, but device complexity increases
Solution Approach 1:
The patent utilizes phase change material (PCM) that transitions between crystalline and amorphous states to modulate light transmission. When the PCM is in the crystalline state, it transmits light to display the organic light emitting layer's color; when amorphous, it blocks light to display a different color or pattern. This phase transition mechanism enables multiple colors and patterns without requiring multiple light emitting layers, thus improving color variety while managing device complexity.
Solution Approach 2:
The second electrode serves dual functions: it acts as the bottom electrode for the organic light emitting diode structure and simultaneously serves as the heating electrode to induce phase changes in the PCM layer. This multi-functionality reduces the need for additional electrodes, thereby improving color variety through PCM modulation while minimizing the increase in device complexity.
2Adaptability or versatility
If multiple light emitting layers with different colors are used to create patterns, then color variety is improved, but device complexity and manufacturing difficulty increase
Solution Approach 1:
Instead of stacking multiple light emitting layers with different colors, the patent uses a single organic light emitting layer combined with a phase change material layer. By controlling the phase state of the PCM through the third electrodes, different regions can selectively transmit or block light, creating multi-color patterns from a single light emitting layer. This approach achieves color variety while significantly reducing device complexity compared to multi-layer structures.
3Adaptability or versatility
If more electrodes are added to control phase change for patterns, then pattern capability is improved, but the number of electrodes and device thickness increase
Solution Approach 1:
The second electrode is designed to serve双重 purposes: as the bottom electrode for electrical injection in the OLED and as the heating electrode to induce phase changes in the PCM. This eliminates the need for a separate heating electrode, reducing the total number of electrodes while maintaining full pattern capability through phase change control.
Solution Approach 2:
The patent merges the function of the bottom electrode and the heating electrode into a single second electrode. This consolidation reduces the number of discrete components, decreases device thickness, and simplifies the overall structure while still enabling precise phase change control for pattern formation through the third electrodes.
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 solution enables the lighting device to display various colors and patterns by controlling the phase change of the phase change material layer, increasing design freedom and reducing the number and thickness of electrodes, while maintaining low power consumption.
Implementation Method 1
a phase change material layer disposed below the second electrode... allowing for the transformation of light color based on the phase change state
Implementation Method 2
electrons and holes from a cathode for injecting electrons and an anode for injecting holes are injected into a light emitting layer and excitons formed by coupling the injected electrons and holes are dropped from an excited state to a ground state to emit light
Data Source
AI summary
A lighting device includes a substrate including a display area and a non-display area and an organic light emitting layer disposed in the display area. A first electrode is disposed on the organic light emitting layer and a second electrode is disposed below the organic light emitting layer. A phase change material layer is disposed below the second electrode and a plurality of third electrodes is disposed between the substrate and the phase change material layer. Therefore, a pattern having various colors of light and various shapes may be implemented based on a shape of the plurality of third electrodes, a phase change of the phase change material layer, and a color of light emitted from the organic light emitting layer.