Organic Light-Emitting Device With Charge Generation Layers
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Solution Overview
Problem
Existing organic light-emitting devices face challenges in achieving low driving voltage and high efficiency while maintaining excellent optical characteristics such as wide viewing angles and high contrast ratios.
Innovation Solution
The organic light-emitting device incorporates multiple emission units with distinct emission wavelengths and charge generation layers, including n-type and p-type charge generation layers, which can include alkali metals or rare-earth metals, to optimize charge transport and light emission efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple emission units with different emission wavelengths are used to achieve full-color images, then the device can produce diverse colors and improve versatility, but the device complexity increases due to the need for multiple charge generation layers and emission units
Solution Approach 1:
The device is divided into multiple emission units (first emission unit, second emission unit, third emission unit) each responsible for different color emissions (red, green, blue). Each emission unit contains its own emission layer with specific emission characteristics, allowing independent optimization of each color channel while maintaining overall device functionality
Solution Approach 2:
The patent transitions from a single emission layer to a multi-layered emission structure with multiple emission units stacked in sequence. This dimensional expansion allows simultaneous achievement of full-color capability and efficient charge management by distributing functions across multiple layers rather than concentrating all functions in a single layer
2Productivity
If charge generation layers are added between emission units to improve charge transport and efficiency, then the device efficiency improves, but the device complexity and manufacturing difficulty increase
Solution Approach 1:
Charge generation layers are introduced as intermediary components between adjacent emission units. These layers facilitate charge transfer and balance between different emission units, ensuring efficient recombination and light emission while preventing charge accumulation. The charge generation layers act as mediators that enable smooth charge flow across the multi-unit structure
Solution Approach 2:
Different charge generation layers are positioned at specific locations between different types of emission units (e.g., between red-green units and between green-blue units). Each charge generation layer is optimized for its specific position to handle the particular charge balance requirements of adjacent emission units, achieving local optimization of charge transport
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 reduces the driving voltage and enhances efficiency, enabling the device to produce high-quality light with improved viewing angles and contrast ratios.
Implementation Method 1
Carriers, such as holes and electrons, recombine in the emission layer to produce excitons. These excitons transition from an excited state to a ground state, thereby generating light.
Data Source
AI summary
An organic light-emitting device is provided That includes: a first electrode; a second electrode facing the first electrode; m number of emission units disposed between the first electrode and the second electrode, the emission units each including at least one emission layer. m−1 charge generation layers are disposed between two adjacent emission units and each includes an n-type charge generation layer and a p-type charge generation layer. Maximum emission wavelengths of light emitted by two emission units may be different. At least one of the emission units, at least one of the charge generation layers, or any combination thereof may each include a first compound, which may be represented by Formula 1: