Polymer Host Material for Phosphorescent OLED Efficiency
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Solution Overview
Problem
Current light emitting devices using polymer compounds as host materials for phosphorescent compounds do not achieve sufficient current efficiency and light emission efficiency.
Innovation Solution
A polymer compound with specific repeating units, including arylene, aromatic heterocyclic, and aromatic amine residues, is developed to enhance the triplet excited state energy level and conductive properties, improving current and light emission efficiencies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional polymer compounds are used as host materials for phosphorescent compounds, then the device structure is simple and ease of manufacture is maintained, but current efficiency and light emission efficiency are insufficient
Solution Approach 1:
The patent modifies the chemical structure parameters of the polymer compound by introducing specific repeating units with formula (11) containing arylene, aromatic heterocyclic, or aromatic amine residues. This structural parameter change raises the T1 energy level and improves conductive properties, thereby enhancing current efficiency and light emission efficiency while maintaining the polymer compound's ease of manufacture through conventional synthesis methods
Solution Approach 2:
The patent creates a composite host material system by combining phosphorescent compounds with specifically designed polymer compounds having repeating units of formula (11). This composite material approach synergistically combines the phosphorescent properties of the dopant with the enhanced energy level and conductive properties of the polymer host, achieving superior current efficiency and light emission efficiency
2Ease of manufacture
If conventional polymer compounds are used as host materials, then manufacturing process is simple, but light emission efficiency is insufficient
Solution Approach 1:
The patent changes the energy level parameters of the host material by incorporating repeating units with formula (11) that have elevated T1 energy levels. This parameter modification reduces energy loss through triplet-triplet annihilation and improves light emission efficiency, while the polymer synthesis process remains relatively simple and manufacturable
Solution Approach 2:
The patent introduces specific functional groups and repeating units with formula (11) at localized positions within the polymer structure to create regions of high energy level and improved conductive properties. This local quality enhancement focuses the efficiency improvement where it is most needed in the light emitting layer without requiring complete restructuring of the entire material system
3Productivity
If host material with high T1 energy level is used to achieve high current efficiency, then current efficiency improves, but device complexity increases
Solution Approach 1:
The patent achieves high current efficiency by modifying the molecular structure parameters of the polymer compound itself, introducing repeating units with formula (11) that inherently possess high T1 energy levels. This material-level parameter change eliminates the need for complex device architecture modifications, maintaining simple device structure while achieving improved current efficiency
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 polymer compound significantly enhances current efficiency and light emission efficiency of light emitting devices, particularly in the blue emission range, while providing a raw material monomer for its production.
Implementation Method 1
a composition obtained by doping a host material with a phosphorescent compound showing light emission from the triplet excited state
Implementation Method 2
a light emitting device comprising an anode, a cathode and an organic layer disposed between the anode and the cathode
Data Source
AI summary
A high-molecular compound including a group indicated by general formula (11) as a repeating unit.In formula (11) n1 indicates an integer of 1-3. Ar1 indicates an arylene group, a divalent aromatic heterocyclic group, or a divalent aromatic amine residue, and these groups may have a substituent group. If there is a plurality of Ar1, the Ar1 can be the same or can be different. R11 indicates a hydrogen atom, an alkyl group, an aryl group, a monovalent aromatic heterocyclic group, or an aralkyl group, and said groups may have a substituent group. The plurality of R11 can be the same or can be different. However, at least three of the R11 are an alkyl group, an aryl group, a monovalent aromatic heterocyclic group, or an aralkyl group.