Light-Emitting Device Adhesive Layer Oxygen Adsorbent
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Solution Overview
Problem
Existing light-emitting devices, such as QLEDs and OLEDs, face challenges in maintaining luminous efficiency due to degradation caused by moisture and oxygen, especially when manufactured in an atmosphere rather than an inert environment. Additionally, the use of porous adsorption sheets to mitigate this issue can block light transmission, interfering with luminescence observation and increasing manufacturing costs.
Innovation Solution
A light-emitting device configuration that includes a substrate with at least one light-emitting element, a cover member with light-transmitting properties, and an adhesive layer containing a curable adhesive, a spacer, and an oxygen adsorbent. This configuration allows for bonding between the substrate and the cover member, effectively sealing the light-emitting element while maintaining light transmission and suppressing oxygen ingress.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a porous adsorption sheet is attached to the upper inner surface of the sealing member to suppress oxygen ingress, then oxygen adsorption capability is improved, but light transmission is blocked which interferes with luminescence observation
Solution Approach 1:
The oxygen adsorbent is extracted from the sealing member interior and relocated to the adhesive layer. This separates the oxygen suppression function from the light transmission path, allowing the adsorbent to function without blocking light. The adhesive layer serves as a carrier that positions the adsorbent away from the optical path while maintaining its oxygen adsorption capability.
Solution Approach 2:
The adhesive layer acts as an intermediary medium that carries the oxygen adsorbent particles. Instead of placing the adsorbent directly in the sealing member where it blocks light, the adhesive layer mediates by distributing the adsorbent particles in a location that provides oxygen suppression without interfering with light transmission to the light-emitting element.
2Reliability
If inert atmosphere processing is used to manufacture light-emitting devices to prevent oxygen degradation, then luminous efficiency is maintained, but manufacturing cost and complexity increase due to equipment investment and maintenance requirements
Solution Approach 1:
The oxygen adsorbent is incorporated into the adhesive layer during the bonding process, performing preliminary oxygen absorption before the light-emitting element can be degraded. This preliminary action eliminates the need for complex inert atmosphere processing equipment, as the adsorbent is already in position to suppress oxygen ingress from the moment of sealing.
Solution Approach 2:
The invention changes the chemical composition parameter of the adhesive layer by incorporating oxygen adsorbent particles. This parameter change transforms the adhesive from a simple bonding material to an active oxygen-suppressing component, enabling atmospheric manufacturing while maintaining device performance.
3Reliability
If the adhesive layer contains an oxygen adsorbent to suppress oxygen ingress, then oxygen adsorption is improved, but the adhesive layer thickness increases which may affect bonding quality
Solution Approach 1:
The oxygen adsorbent particles are distributed locally within the adhesive layer at concentrations optimized for oxygen suppression. Rather than uniformly increasing thickness, the adsorbent particles provide the necessary oxygen adsorption capability within the existing adhesive layer thickness, maintaining bonding quality while suppressing oxygen ingress.
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 proposed solution enables the manufacture of light-emitting devices with suppressed decreases in external quantum efficiency, even when produced in an atmosphere, without interfering with luminescence observation. It also reduces manufacturing costs by eliminating the need for inert atmosphere processing.
Implementation Method 1
an adhesive layer containing a curable adhesive, a spacer, and an oxygen adsorbent
Implementation Method 2
bonding the substrate and the cover member in the atmosphere with an adhesive layer made of the adhesive layer material as the adhesive layer interposed between the substrate and the cover member by curing the curable adhesive
Data Source
AI summary
A light-emitting device includes a substrate, at least one light-emitting element provided on the substrate, a cover member that covers the at least one light-emitting element, and an adhesive layer that is provided between the substrate and the cover member, surrounds the light-emitting element, and bonds a peripheral portion of the cover member to the substrate. The adhesive layer contains a curable adhesive, a spacer, and an oxygen adsorbent.