Platinum Complex Phosphorescent Material for OLED Efficiency and Durability
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Solution Overview
Problem
Existing organic electroluminescent devices face challenges in achieving both high efficiency and durability, particularly in developing phosphorescent materials that emit light of shorter wavelengths such as green to blue, while current platinum complexes with quadridentate ligands are limited to longer wavelengths and lack durability.
Innovation Solution
The use of a platinum complex with a specific cyclic or non-cyclic quadridentate ligand structure in the organic electroluminescent device, where the complex is incorporated into the light-emitting layer, enhancing luminance, efficiency, and durability by providing high external quantum efficiency and improved emission characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If phosphorescence-emitting materials such as iridium complexes or platinum complexes are used to improve luminous efficiency, then external quantum efficiency is improved, but device durability deteriorates
Solution Approach 1:
The invention changes the chemical structure parameters of the phosphorescent material by using a specific platinum complex with a quadridentate ligand containing nitrogen-containing heterocycles (Z1 and Z2) coordinated through nitrogen atoms. This structural parameter change enables both high external quantum efficiency (19% or more) and improved device durability, resolving the contradiction between efficiency and durability.
Solution Approach 2:
The invention employs a composite ligand structure combining nitrogen-containing heterocycles (Z1 and Z2) with other coordinating groups (Q1 and Q2) to form a quadridentate ligand. This composite material approach creates a platinum complex that simultaneously achieves high phosphorescence efficiency for high external quantum efficiency and enhanced stability for improved durability.
2Ease of manufacture
If platinum complexes with quadridentate ligands are used to achieve shorter wavelength emission (green to blue), then emission wavelength is shortened, but the ligand structure is limited to bipyridyl or phenanthroline skeletons
Solution Approach 1:
The invention changes the ligand structure parameters by introducing nitrogen-containing heterocycles (Z1 and Z2) as coordinating groups in the quadridentate ligand. This parameter change enables the platinum complex to emit light in the green to blue region (shorter wavelengths) while providing structural flexibility beyond traditional bipyridyl or phenanthroline skeletons.
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 platinum complex-based organic electroluminescent device achieves high luminance, high external quantum efficiency, and improved durability, enabling efficient blue to green light emission with enhanced device performance.
Implementation Method 1
use of a phosphorescence-emitting material. Iridium complexes, platinum complexes, and the like are such a phosphorescence-emitting material
Implementation Method 2
Z1 and Z2 each independently represent a nitrogen-containing heterocycle coordinated with the platinum through a nitrogen atom
Data Source
AI summary
An organic electroluminescent device having a pair of electrodes and at least one organic layer including a light-emitting layer interposed between the pair of electrodes, in which the organic layer contains at least one compound represented by formula (I):wherein Z1 and Z2 each independently represent a nitrogen-containing heterocycle coordinated with the platinum through a nitrogen atom; Q1 and Q2 each independently represent a group bonded with the platinum through a carbon atom, an oxygen atom, a sulfur atom, a nitrogen atom or a phosphorous atom; Q1 and Q2 each represent a structure different from each other; L1 and L2 each independently represent a single bond or a linking group; and n represents 0 or 1.