Organic EL Device Manufacturing with Light-Restricted Sealing
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Solution Overview
Problem
Organic electroluminescent materials with an anthracene skeleton degrade when exposed to light with higher energy than singlet excitation energy, especially in environments containing oxygen, leading to inferior luminous efficiency and durability in manufactured devices.
Innovation Solution
The method involves forming and processing organic electroluminescent devices in an atmosphere where the organic compound layer is not exposed to oxygen and light with wavelengths shorter than the absorption spectrum edge of the anthracene skeleton, using a sealing member to protect the devices and restricting the ambient light spectrum to prevent photodimerization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the organic compound layer containing anthracene skeleton is exposed to light with higher energy than singlet excitation energy in an oxygen-containing atmosphere, then the organic electroluminescent material is degraded through photodimerization, but this degradation reduces luminous efficiency and durability
Solution Approach 1:
The patent applies preliminary action by forming the organic compound layer containing anthracene skeleton and immediately providing the sealing member to cover it, before any harmful light exposure can occur. The sealing member is provided in advance to create a protective environment that prevents oxygen and harmful light from reaching the organic compound layer, thus preventing photodimerization degradation before it can happen.
Solution Approach 2:
The patent creates an inert atmosphere by using a sealing member that excludes oxygen and restricts light spectrum from reaching the organic compound layer. The sealed environment acts as an inert atmosphere that prevents the chemical reactions (photodimerization) that would otherwise occur when the anthracene-containing compound is exposed to oxygen and high-energy light.
2Ease of manufacture
If conventional photolithography processes are used with white luminescent lamps, then manufacturing steps can be completed, but the organic electroluminescent material degrades due to unrestricted ambient light spectrum
Solution Approach 1:
The patent applies parameter changes by restricting the light spectrum parameter in the manufacturing environment. Instead of using conventional white luminescent lamps with unrestricted spectrum, the patent restricts the ambient light to wavelengths longer than the absorption spectrum edge of the anthracene skeleton, thereby preventing photodimerization while still allowing photolithography processes to be completed.
Solution Approach 2:
The patent provides the sealing member as a preliminary protective measure before completing the photolithography process. This preliminary action ensures that even if white luminescent lamps are used during manufacturing steps, the organic compound layer remains protected from harmful light exposure, maintaining both ease of manufacture and patterning accuracy.
3Productivity
If the organic compound layer is exposed to oxygen and high-energy light during processing, then standard manufacturing procedures can be followed, but the luminous efficiency and durability of the final device are inferior to vacuum evaporation devices
Solution Approach 1:
The patent creates an inert environment by sealing the organic compound layer with a sealing member that excludes oxygen and restricts light spectrum. This inert environment allows standard manufacturing procedures to be followed while preventing the degradation that would reduce luminous efficiency and durability, thus resolving the contradiction between productivity and reliability.
Solution Approach 2:
The sealing member is provided as a preliminary protective measure that maintains the integrity of the organic compound layer throughout the manufacturing process. This preliminary protection enables high-speed manufacturing procedures while ensuring the device achieves luminous efficiency and durability comparable to vacuum evaporation devices.
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 luminous efficiency and durability of organic electroluminescent devices by preventing degradation, resulting in high-definition, high-efficiency, and long-lasting displays.
Implementation Method 1
When the organic electroluminescent material having an anthracene skeleton is exposed to light having higher energy than singlet excitation energy under an atmosphere containing oxygen, however, the organic electroluminescent material is degraded through photodimerization.
Implementation Method 2
the organic electroluminescent material is degraded through photodimerization
Data Source
AI summary
A method for manufacturing an organic electroluminescent display apparatus including a plurality of organic electroluminescent devices at least containing a fused ring compound having an anthracene skeleton, includes, in the following order: forming an organic electroluminescent layer on a substrate on which a first electrode has been formed; processing the organic electroluminescent layer; forming a second electrode on the organic electroluminescent layer; and providing a sealing member covering the organic electroluminescent layer, in which the organic electroluminescent layer is not exposed to an environment containing oxygen and including light of a wavelength shorter than a wavelength of a long wavelength edge of an absorption spectrum of the fused ring compound having an anthracene skeleton from forming the organic electroluminescent layer until completion of providing the sealing member.