OLED White Light Stability via Phosphor Conversion and Segmented Deposition
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Organic light emitting diode devices face limitations in depositing emission layers for larger displays using fine shadow masks, leading to unstable color characteristics and efficiency issues in white light emission.
Innovation Solution
The use of multiple light emitters with charge-generating layers between them, combined with a filler layer containing additional light emitters, to achieve stable white light emission by combining colors from different emitters, rather than sequentially laminating emission layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If emission layers are deposited in each sub-pixel using a fine shadow mask, then color characteristics can be controlled per sub-pixel, but the method becomes limited for larger display devices and manufacturing complexity increases
Solution Approach 1:
The display device is divided into three separate emission layers (red, green, blue) that are sequentially deposited across the entire display area using a single shadow mask, rather than depositing all three colors simultaneously in each sub-pixel. This segmentation of the emission layer deposition process resolves the technical contradiction by maintaining color control while simplifying the manufacturing process for larger displays
Solution Approach 2:
The patent transitions from a planar deposition approach to a sequential multi-layer approach, adding the dimension of time (sequential deposition) to solve the manufacturing complexity issue. By depositing emission layers in sequence across the entire display area rather than simultaneously in each sub-pixel, the method enables larger display fabrication while maintaining color precision
2Adaptability or versatility
If white light is emitted by sequentially accumulating red, blue, and green emission layers and using color filters, then full colors can be expressed, but the white light emission becomes unstable with poor color characteristics and efficiency
Solution Approach 1:
The patent extracts and removes the color filter component from the traditional white light emission structure. Instead of using red, green, and blue emission layers with color filters to achieve full color, the invention uses a single blue emission layer combined with yellow phosphor particles to generate full color through photoluminescence, eliminating the source of color characteristic instability and efficiency loss
Solution Approach 2:
The patent changes the fundamental parameter of light generation from direct electroluminescence through multiple emission layers to photoluminescence conversion. By using blue light excitation of yellow phosphor particles, the system achieves stable white light emission with improved color characteristics and efficiency, resolving the reliability issue while maintaining full color expression capability
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 approach enhances the current efficiency and lifespan of the device while providing stable white light emission by combining colors from multiple emitters, overcoming the limitations of traditional methods.
Implementation Method 1
a yellow phosphor layer including yellow phosphor particles
Data Source
AI summary
An organic light emitting diode device is disclosed. The organic light emitting diode device includes: a first electrode, a light emitting section disposed over the first electrode and including at least two light emitters displaying the same or different colors, a second electrode disposed over the light emitting section, and a filler layer for encapsulation disposed over the second electrode and including a light emitter displaying at least one color.