Light Emitting Device Crosslinked Organic Layer Luminance Life
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing light emitting devices suffer from inadequate luminance life, which is a limitation in their display and illumination applications.
Innovation Solution
A light emitting device is designed with a specific configuration comprising an anode, a cathode, a first organic layer containing a phosphorescent compound represented by formula (1), and a second organic layer comprising a crosslinked body of a crosslinkable material, where the crosslinkable material is a low molecular weight compound or polymer with crosslinkable groups, enhancing the luminance life.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If a conventional organic layer configuration is used, then the device structure is simple, but the luminance life is insufficient
Solution Approach 1:
The organic layer is divided into two distinct functional layers: a first organic layer containing the phosphorescent compound and a second organic layer comprising the crosslinked body. This segmentation allows each layer to perform its specific function optimally, with the second layer providing enhanced stability and longevity through crosslinking, thereby resolving the contradiction between improved luminance life and increased structural complexity.
Solution Approach 2:
The patent employs a composite material system where the second organic layer uses a crosslinked body formed from crosslinkable materials (such as silane crosslinked compounds or epoxy crosslinked compounds). This composite approach combines the light-emitting properties of the phosphorescent compound in the first layer with the enhanced mechanical and chemical stability of the crosslinked second layer, achieving extended luminance life while maintaining a manageable device structure.
2Duration of action of stationary object
If the second organic layer uses crosslinkable material, then the luminance life is improved, but the manufacturing process becomes more complex
Solution Approach 1:
The patent specifies particular parameter ranges for the crosslinkable materials, including molecular weight (100 to 10,000), crosslinkable group content (0.1 to 10 mmol/g), and composition ratios in the second organic layer (5 to 95 mass%). By optimizing these parameters, the crosslinking process achieves effective luminance life improvement while maintaining manufacturability through controlled chemical reactions rather than complex multi-step processes.
Solution Approach 2:
The patent employs commercially available crosslinkable materials such as silane crosslinked compounds and epoxy crosslinked compounds that can be readily procured and processed. These materials enable effective crosslinking through straightforward processes (such as moisture-cured or heat-cured methods) without requiring specialized equipment or multi-step manufacturing procedures, thus improving luminance life while preserving ease of manufacture.
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 device exhibits improved luminance life, effectively addressing the limitations of previous devices by incorporating a crosslinked second organic layer that enhances stability and performance.
Implementation Method 1
a first organic layer which is a layer comprising a phosphorescent compound represented by formula (1) and a compound represented by formula (H)
Implementation Method 2
a second organic layer which is a layer comprising a crosslinked body of a crosslinkable material
Data Source
AI summary
To provide a light emitting device excellent in luminance life. Disclosed is a light emitting device comprising an anode, a cathode, and a first organic layer and a second organic layer disposed between the anode and the cathode, wherein the first organic layer is a layer comprising a phosphorescent compound represented by formula (1) and a compound represented by formula (H), and the second organic layer is a layer comprising a crosslinked body of a crosslinkable material: wherein M represents an iridium atom or the like, n1 represents an integer of 1 or more, n2 represents an integer of 0 or more, E1 and E2 each represent a carbon atom or the like, ring L1 represents an aromatic heterocyclic ring, ring L2 represents an aromatic hydrocarbon ring or the like, and A1-G1-A2 represents an anionic bidentate ligand: wherein nH1 represents an integer of 0 to 5, nH2 represents an integer of 1 to 10, ArH1 represents a group represented by formula (H1-1), LH1 represents an alkylene group, an arylene group or the like, and ArH2 represents an aromatic heterocyclic group or the like: wherein ring RH1 and ring RH2 each represent a monocyclic or fused-ring aromatic heterocyclic ring, or the like, and XH1 represents a single bond or the like.