Organic Light Emitting Device Interference Pattern Optimization
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Solution Overview
Problem
Current organic light emitting devices with different color light emitting layers suffer from insufficient light extraction efficiency, limiting their luminance and lifespan, which hinders the development of next-generation displays like high-luminance televisions.
Innovation Solution
The organic light emitting device incorporates a stack structure with a first and second light emitting unit between electrodes, where the first electrode reflects light to generate an interference pattern, optimizing the placement of interference positions within each light emitting layer to enhance light extraction efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If stack type organic light emitting devices with multiple light emitting units are used, then device lifespan is improved, but light extraction efficiency remains insufficient
Solution Approach 1:
The device is divided into multiple light emitting units (first light emitting unit with first light emitting layer, second light emitting unit with second light emitting layer) separated by a connection layer. Each unit can be independently optimized for different wavelengths, allowing targeted improvement of light extraction efficiency for each color while maintaining overall device lifespan through the stack configuration.
Solution Approach 2:
Different light emitting layers are positioned at specific depths from the reflective electrode to create localized interference patterns optimized for their respective wavelengths. The first light emitting layer is positioned to create constructive interference for its wavelength, and the second light emitting layer is positioned similarly for its wavelength, ensuring each region of the device has optimal light extraction properties for its function.
2Duration of action of stationary object
If initial luminance is decreased to extend device life, then lifespan is improved, but practical application is limited
Solution Approach 1:
The invention changes the optical parameters of the device by introducing a reflective electrode and positioning light emitting layers at specific depths to create constructive interference patterns. This increases the light extraction efficiency and initial luminance without increasing the injected electric charge, thereby extending device lifespan while maintaining high luminance output.
3Adaptability or versatility
If light emitting layers for different colors are used, then color display capability is improved, but light extraction efficiency for all colors is insufficient
Solution Approach 1:
The device segments the light emitting function into multiple independent units, each responsible for a specific color wavelength. This allows each unit to be optimized independently for its wavelength through specific positioning relative to the reflective electrode, ensuring high light extraction efficiency for each color while maintaining overall color display capability.
Solution Approach 2:
Each light emitting layer is positioned at a specific depth from the reflective electrode to create localized constructive interference patterns optimized for its wavelength. This ensures that each color component achieves maximum light extraction efficiency at its designated location, resolving the issue of insufficient extraction efficiency across all colors.
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 the extraction efficiency of light from both color light emitting layers, enabling high luminance displays and reducing power consumption by effectively utilizing the interference pattern to enhance light emission.
Implementation Method 1
The first electrode reflects light from at least one of the light emitting units to generate an interference pattern with light emitted from the first light emitting layer
Implementation Method 2
The first electrode reflects light from at least one of the light emitting units to generate an interference pattern with light emitted from the first light emitting layer. The interference pattern has a plurality of interference positions
Data Source
AI summary
An organic light emitting device includes a first electrode and second electrode on a substrate. Light emitting units are positioned between the first and second electrodes. A first light emitting unit includes a first light emitting layer, and a second light emitting unit includes a second light emitting layer. The first electrode reflects light from at least one of the light emitting units to generate an interference pattern with light emitted from the first light emitting layer. The interference pattern has a plurality of interference positions such that a first interference position is located within the first light emitting layer, and a second interference position is located within the second light emitting layer.