Cap Layer Positioning in Organic Light-Emitting Apparatus
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Solution Overview
Problem
In active matrix light-emitting apparatuses, the resin layer in the external region comes into contact with organic protective layers, leading to moisture and gas transfer to the light-emitting region, degrading the organic electroluminescent elements, and existing solutions like high-energy film formation methods can damage the organic compound layers.
Innovation Solution
A cap layer is introduced on the organic electroluminescent element, formed using known organic compound materials and vacuum heating evaporation methods, with its end located closer to the light-emitting region than the second electrode, ensuring it does not contact the resin layer and preventing moisture and gas transfer, while also serving as a light interference layer to enhance luminous efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a protective layer is formed by high-energy film formation method (sputtering or plasma CVD), then the organic electroluminescent element is protected from moisture and oxygen, but the organic compound layer may be damaged
Solution Approach 1:
A cap layer made of organic compound is introduced as an intermediary layer between the resin layer and the organic electroluminescent element. This cap layer serves as a buffer that prevents direct contact between the resin and the sensitive organic layers, while also providing moisture and gas barrier properties. The cap layer is formed by vacuum heating evaporation method which is low-energy and does not damage the organic compound layer.
Solution Approach 2:
The invention uses a composite structure combining organic cap layer with the organic electroluminescent element. The cap layer is formed from organic compound materials that are compatible with the underlying organic layers, creating a composite protective system that provides both mechanical protection and moisture barrier functionality without using high-energy inorganic coating methods.
2Device complexity
If the resin layer is disposed to come into direct contact with the organic protective layer, then the structure is simplified, but moisture and gases transfer from the resin layer to the light-emitting region through the protective layer
Solution Approach 1:
The cap layer acts as an intermediary barrier between the resin layer and the organic electroluminescent element. It prevents direct contact while maintaining structural simplicity, and effectively blocks the transfer of moisture and gases from the resin layer to the light-emitting region through the organic compound structure.
Solution Approach 2:
The cap layer is formed as a thin film structure that provides effective barrier properties against moisture and gas transfer. This thin organic film prevents harmful substance penetration while maintaining the overall structural simplicity and flexibility of the device.
3Strength
If the cap layer is formed by vacuum heating evaporation method, then the organic compound layer is not damaged, but the formation process requires vacuum environment
Solution Approach 1:
The invention replaces high-energy mechanical film formation methods (such as sputtering) with vacuum heating evaporation method. This substitution uses thermal energy in vacuum environment to deposit the cap layer, which is gentler on organic materials and prevents damage to the organic compound layer while still providing effective protection.
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
The cap layer effectively suppresses the transfer of moisture and gases from the resin layer to the light-emitting region, reducing degradation of the organic electroluminescent elements and improving luminous efficiency by controlling refractive index and film thickness.
Implementation Method 1
the cap layer effectively suppresses the transfer of moisture and gases from the resin layer to the light-emitting region
Implementation Method 2
formed using known organic compound materials and vacuum heating evaporation methods
Implementation Method 3
serving as a light interference layer to enhance luminous efficiency. The cap layer effectively suppresses the transfer of moisture and gases from the resin layer to the light-emitting region, reducing degradation of the organic electroluminescent elements and improving luminous efficiency by controlling refractive index and film thickness
Data Source
AI summary
In a light-emitting apparatus including a cap layer disposed on a second electrode and a contact portion, which is disposed in an external region outside the light-emitting region and which electrically connects the second electrode to the drive circuit, the formation end of the cap layer is located in the side nearer to the light-emitting region than is the formation end of the second electrode.