Organometallic Complex Electron-Withdrawing Groups Phosphorescence
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Solution Overview
Problem
Current light-emitting elements using fluorescent materials have limited quantum efficiency and chromaticity, while phosphorescent materials offer higher efficiency but require development of effective organometallic complexes for improved performance.
Innovation Solution
Development of organometallic complexes with specific structures, such as those represented by general formulas (1) to (4), incorporating electron-withdrawing groups and heavy metals like iridium or platinum, which enhance phosphorescence emission intensity and chromaticity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If fluorescent materials are used in light-emitting elements, then the device structure is simpler, but the quantum efficiency is limited and luminous efficiency is lower
Solution Approach 1:
The patent changes the material parameter from fluorescent to phosphorescent emitting materials, and introduces heavy metal elements (Ir, Pt) to alter the emission mechanism. This parameter change enables triplet state utilization through phosphorescence, achieving internal quantum efficiency exceeding 25% while maintaining device feasibility
Solution Approach 2:
The patent employs composite material structures by combining heavy metal complexes (Ir or Pt based) with organic ligands containing electron-withdrawing groups. This composite approach creates phosphorescent materials that leverage both the heavy atom effect for spin-orbit coupling and the electron-withdrawing groups for enhanced emission intensity, resolving the efficiency limitation
2Loss of energy
If phosphorescent materials are used to improve quantum efficiency, then luminous efficiency increases, but the chromaticity and emission characteristics require further optimization
Solution Approach 1:
The patent applies local quality modification by introducing electron-withdrawing groups at specific positions within the organic ligand structure. This localized structural modification at R1-R6 positions enables precise control over the emission wavelength and chromaticity, achieving reddish emission with good chromaticity while maintaining high quantum efficiency
Solution Approach 2:
The patent systematically varies the ligand structure parameters, including introducing electron-withdrawing groups and modifying the organic framework, to precisely tune the emission characteristics. This parameter optimization achieves internal quantum efficiency exceeding 25% with improved chromaticity and reddish emission
3Ease of manufacture
If conventional organometallic complexes are used, then the synthesis is relatively straightforward, but the phosphorescence emission intensity is insufficient
Solution Approach 1:
The patent modifies the chemical structure parameters of the organometallic complex by incorporating electron-withdrawing groups into the ligand system. This structural parameter change enhances the phosphorescence emission intensity through improved spin-orbit coupling and radiative transition rates, while maintaining feasibility for conventional synthesis methods
Solution Approach 2:
The patent creates enhanced organometallic complexes by combining heavy metal centers (Ir or Pt) with specially designed organic ligands containing electron-withdrawing groups. This composite structure leverages the heavy atom effect for strong spin-orbit coupling and the electron-withdrawing groups for enhanced emission intensity, achieving internal quantum efficiency exceeding 25%
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 organometallic complexes achieve higher phosphorescence emission intensity and improved chromaticity, leading to more efficient light-emitting elements with better quantum efficiency and reddish emission characteristics.
Implementation Method 1
an organometallic complex which emits light by current excitation... an organometallic complex including a structure as represented by general formulae (1) or (2) can emit phosphorescence
Implementation Method 2
By virtue that the Ar has an electron-withdrawing group, an organometallic complex which emits phosphorescence with higher emission intensity can be obtained
Data Source
AI summary
A material which can emit phosphorescence is disclosed. Further, a light-emitting element having good chromaticity is disclosed. An embodiment of the present invention is an organometallic complex including a structure as represented by the general formula (1): wherein R1 represents an alkyl group having 1 to 4 carbon atoms; each of R2 to R5 represents any one of hydrogen, a halogen element, an acyl group, an alkyl group, an alkoxyl group, an aryl group, a cyano group, and a heterocyclic group; Ar represents an aryl group or a heterocyclic group, preferably, an aryl group having an electron withdrawing group or a heterocyclic group having an electron withdrawing group; and M represents a Group 9 element or a Group 10 element. By virtue that the Ar has an electron withdrawing group, an organometallic complex which emits phosphorescence with higher emission intensity can be obtained.