OLED Dual-Layer Area Ratio for Color Temperature
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Solution Overview
Problem
Existing organic electroluminescent devices face high process complexity and low yield due to the need for precise fabrication of multiple organic electroluminescent material layers to achieve desired color temperatures, requiring high accuracy and resulting in high production costs.
Innovation Solution
The organic electroluminescent device comprises a first light emitting layer and a second light emitting layer, where the second layer is arranged on the first layer with a specific light emitting area ratio, allowing for mixed light emission by adjusting the opening ratio of organic material layers using a fine metal mask, reducing the need for precise fabrication and enabling flexible color temperature adjustment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple organic electroluminescent material layers are precisely fabricated to achieve desired color temperatures, then color temperature accuracy is improved, but process complexity increases and yield decreases
Solution Approach 1:
The device segments the light emitting function into two distinct layers: a first light emitting layer and a second light emitting layer. Each layer emits light of different colors, and their combined emission achieves the desired color temperature. This segmentation allows each layer to be optimized independently, reducing the overall process complexity while maintaining color temperature accuracy.
Solution Approach 2:
The patent introduces a spatial dimension solution by stacking light emitting layers vertically rather than mixing materials horizontally. The second light emitting layer is positioned on top of the first light emitting layer, creating a vertical structure where each layer contributes to the overall color output. This dimensional approach simplifies the fabrication process compared to traditional methods requiring precise lateral patterning.
2Measurement precision
If multiple organic electroluminescent material layers are precisely fabricated to achieve desired color temperatures, then color temperature accuracy is improved, but productivity decreases
Solution Approach 1:
By dividing the light emitting function into separate layers, each layer can be fabricated using standardized processes. The first light emitting layer and second light emitting layer are formed independently, allowing for better process control and higher yield. This segmentation eliminates the need for complex multi-step patterning operations that reduce productivity.
Solution Approach 2:
The first light emitting layer serves multiple functions: it emits light of a specific color and also serves as a carrier transport layer for the second light emitting layer. This multi-functionality reduces the total number of layers required, simplifying the overall structure and improving manufacturing efficiency while maintaining color temperature accuracy.
3Adaptability or versatility
If light emitting area ratio is adjusted to achieve desired color mixing, then color temperature flexibility is improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent controls the light emitting area ratio of the second light emitting layer relative to the first light emitting layer to achieve different color temperatures. By adjusting this area ratio parameter, the device can flexibly control the mixing ratio of emitted lights. This parameter-based control approach is simpler and more robust than precise material thickness control or lateral positioning, reducing manufacturing precision requirements while maintaining color temperature flexibility.
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 simplifies the fabrication process, increases product yield, and allows for flexible adjustment of mixing ratios, reducing production costs and process difficulty while maintaining accurate color temperature specifications.
Implementation Method 1
An OLED emits light under the mechanism that upon application of an external electric field, an electron and hole are injected from a cathode and an anode into an organic electroluminescent material respectively, so as to migrate in the organic electroluminescent material, and recombine to emit light.
Data Source
AI summary
An organic electroluminescent device, a method for fabricating the same, and a light emitting apparatus are disclosed. The organic electroluminescent device comprises a first light emitting layer and a second light emitting layer arranged on a surface of the first light emitting layer at a first side, and partially covers the surface of the first light emitting layer at the first side. Both the first and second light emitting layers are made from a material which has a larger mobility for a first carrier than a second carrier. Light emitting regions of the second light emitting layer and the regions of the first light emitting layer not covered by the second light emitting layer are configured to emit light of different colors at a preset light emitting ratio. A light emitting area ratio between a surface of each light emitting region and surfaces of the regions of the first light emitting layer not covered by the second light emitting layer is preset according to the preset light emitting ratio.