OLED Compound for Charge-Balanced Emission and Color Purity
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Solution Overview
Problem
Existing organic electronic elements face challenges in achieving high efficiency, long lifetime, and stability due to issues with charge balance at the interface of the hole transport layer, low glass transition temperature of materials, and penetration of metal oxides, which affect color purity and lifespan.
Innovation Solution
A novel compound represented by Formula (1) is introduced for use in organic electronic elements, enhancing luminous efficiency, stability, and lifetime by improving the properties of the hole transport layer and emitting-auxiliary layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a hole transport layer with low HOMO value is used, then hole transport function is achieved, but exciton transfer to the hole transport layer occurs causing charge unbalance and light emission at the interface, lowering color purity and efficiency
Solution Approach 1:
An emitting-auxiliary layer is introduced as an intermediary between the hole transport layer and the emitting layer. This auxiliary layer has a HOMO level positioned between the hole transport layer and the emitting layer, preventing direct exciton transfer to the hole transport layer while maintaining efficient charge transport and exciton utilization, thereby resolving the charge unbalance and color purity issues
Solution Approach 2:
The HOMO energy level parameter of the layer between the hole transport layer and emitting layer is specifically optimized to be higher than that of the hole transport layer but lower than that of the emitting layer. This parameter change prevents exciton transfer to the hole transport layer while maintaining efficient charge transport, thereby improving color purity and efficiency
2Adaptability or versatility
If the glass transition temperature of hole transport layer material is low, then material flexibility is improved, but uniformity of thin film surface is lowered and heat resistance is reduced, affecting device lifetime
Solution Approach 1:
The glass transition temperature parameter of the hole transport layer material is increased to enhance heat resistance and thin film uniformity while maintaining adequate flexibility. This parameter optimization prevents material degradation at operating temperatures and ensures consistent thin film morphology, thereby improving device lifetime
Solution Approach 2:
A composite hole transport layer structure is implemented, combining materials with different glass transition temperatures and properties. This composite structure achieves both flexibility and heat resistance by leveraging the complementary characteristics of the constituent materials, resolving the contradiction between flexibility and thermal stability
3Productivity
If efficiency is increased, then driving voltage is decreased, but crystallization of organic material due to joule heating is reduced, affecting lifetime
Solution Approach 1:
The patent converts the potentially harmful effect of joule heating into a beneficial outcome by optimizing the energy level alignment and material properties to ensure that the heat generated during high-efficiency operation remains within acceptable ranges, preventing crystallization while maintaining high efficiency and long lifetime
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 compound achieves high luminous efficiency, low driving voltage, and improved heat resistance, leading to enhanced color purity and extended lifetime of the organic electronic elements.
Implementation Method 1
organic light emitting phenomenon refers to a phenomenon that converts electric energy into light energy by using an organic material
Implementation Method 2
a material for forming an organic material layer in an element such as a hole injection material, a hole transport material, a light emitting material, an electron transport material, an electron injection material, an emitting-auxiliary layer material should be supported by stable and efficient materials
Data Source
AI summary
Provided are an OLED compound, an organic electronic element employing the compound, and an electronic device comprising the element, where the compound improves the luminous efficiency, stability and lifetime of the organic electronic element.