OLED Charge Generation Layer Thickness Optimization
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Solution Overview
Problem
The existing organic light emitting display (OLED) apparatus faces challenges in maintaining a balance of holes and electrons between electrodes, leading to increased driving voltage and reduced lifespan when attempting to improve color reproduction and picture quality by increasing the number of light-emitting layers.
Innovation Solution
The OLED apparatus incorporates a specific structure with optimized charge generation layers, where the thickness of the first charge generation layer is 1.4 to 1.6 times that of the second, ensuring a balanced electron supply to multiple stacks, comprising a reflective anode and transparent cathode with multiple light-emitting layers and charge generation layers to maintain charge balance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the number of stacks or light-emitting layers is increased to improve color coordinates and color reproduction ratio, then picture quality is improved, but driving voltage increases and lifespan decreases
Solution Approach 1:
The patent applies local quality by differentiating the thickness of charge generation layers at different positions. The first charge generation layer has a thickness of 50-150 nm while the second has 30-80 nm, creating localized thickness variations that optimize charge supply to different stacks independently, thereby maintaining low driving voltage while supporting multiple light-emitting layers for high picture quality
Solution Approach 2:
The patent changes the thickness parameter of charge generation layers to resolve the contradiction. By setting specific thickness ranges (50-150 nm for first layer, 30-80 nm for second layer), the patent optimizes charge generation and transport efficiency, enabling multiple light-emitting layers to operate at lower driving voltages while maintaining excellent color reproduction ratio and picture quality
2Manufacturing precision
If the number of stacks is increased to improve color reproduction, then color quality is improved, but device complexity increases
Solution Approach 1:
The patent uses local quality by implementing differentiated charge generation layer thicknesses (50-150 nm for first layer, 30-80 nm for second layer) between stacks. This localized optimization enables efficient charge management in multi-stack configurations, achieving excellent color reproduction while managing the complexity of multiple light-emitting layers through systematic thickness control
3Manufacturing precision
If multiple light-emitting layers are deposited to improve picture quality, then color reproduction is improved, but driving voltage increases and lifespan decreases
Solution Approach 1:
The patent changes the thickness parameter of charge generation layers to specific ranges (50-150 nm for first layer, 30-80 nm for second layer) to optimize charge generation efficiency. This parameter optimization enables multiple light-emitting layers to operate with balanced charge supply, achieving high picture quality while maintaining low driving voltage and extending device lifespan through improved charge management
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 effectively lowers the driving voltage and enhances the lifespan of the OLED apparatus while maintaining high picture quality by ensuring balanced electron and hole flow between electrodes.
Implementation Method 1
determining a thickness of each of charge generation layers for supplying charge to a plurality of stacks in consideration of a balance of holes and electrons between two electrodes
Implementation Method 2
producing excitons through a recombination of holes and electrons, which are respectively injected from the anode and the cathode, in a light emitting layer, and generating light with a specific wavelength by an energy emission of the produced excitons
Data Source
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AI summary
Disclosed is an organic light emitting display (OLED) apparatus (1000) which facilitates to lower a driving voltage and to improve a lifespan by optimizing a balance of electrons and holes among a plurality of stacks (510, 520, 530), wherein the OLED apparatus (1000) may include the plurality of stacks (510, 520, 530) disposed between an anode (400) and a cathode (600), and a plurality of charge generation layers (540, 550) for supplying charges to the plurality of stacks (510, 520, 530), wherein a thickness (T1) of the charge generation layer (540) disposed relatively close to the anode (400) is relatively larger than a thickness (T2) of the charge generation layer (550) disposed relatively close to the cathode (600).