OLED Light-Emitting Element Thermal Stability via NBPhen Layer
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Solution Overview
Problem
Organic light-emitting elements (OLEDs) degrade at high temperatures, leading to reduced performance and reliability in applications such as in-vehicle displays exposed to high temperatures, which affects their heat resistance, luminance, and drive voltage stability.
Innovation Solution
A light-emitting element structure incorporating a layer with 2,9-bis(naphthalen-2-yl)-4,7-diphenyl-1,10-phenanthroline (NBPhen) and a condensed aromatic or heteroaromatic compound, where the NBPhen layer is in contact with the condensed aromatic compound layer, enhancing thermal and electrical stability, and including iridium for phosphorescent emission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If organic compounds are used to form the light-emitting element layers, then the element can be made thin and lightweight with low power consumption, but the element deteriorates and becomes inoperative when placed in high temperature environments
Solution Approach 1:
The patent changes the chemical parameters of the organic compounds by selecting specific condensed aromatic compounds and NBPhen derivatives with particular molecular structures and properties that exhibit higher thermal stability, thereby improving heat resistance while maintaining the inherent advantages of organic EL elements
Solution Approach 2:
The patent uses composite material structures by combining multiple organic compounds including condensed aromatic compounds, NBPhen derivatives, and other auxiliary compounds in layered configurations to achieve both thinness and improved heat resistance through synergistic effects of the composite organic materials
2Reliability
If conventional organic compound layers are used, then the structure remains simple and thin, but luminance degradation and drive voltage changes occur at high temperatures
Solution Approach 1:
The patent segments the electron transport layer into multiple sub-layers, each containing specific compounds with distinct functions: one layer contains condensed aromatic compounds for thermal stability, another contains NBPhen derivatives for electron transport, and additional layers contain auxiliary compounds for luminance stability, thereby achieving reliable high-temperature performance through functional segmentation
Solution Approach 2:
The patent applies local quality by assigning different compound compositions to different regions/layers of the electron transport layer, where each local region is optimized for specific properties: thermal stability in one region, electron transport in another, and luminance stability in a third, thereby improving overall reliability without uniformly increasing complexity
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 proposed structure significantly improves heat resistance, maintains low power consumption, and reduces luminance degradation and drive voltage changes at high temperatures, ensuring high reliability and efficiency of the OLEDs.
Implementation Method 1
research and development of a light-emitting element (organic EL element) which uses an organic compound and utilizes electroluminescence (EL)
Implementation Method 2
The EL layer includes a layer containing a condensed aromatic compound or a condensed heteroaromatic compound
Implementation Method 3
a layer containing 2,9-bis(naphthalen-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBPhen) in contact with the layer containing the condensed aromatic compound or the condensed heteroaromatic compound
Implementation Method 4
including iridium for phosphorescent emission
Data Source
AI summary
A light-emitting element with improved heat resistance is provided without losing its advantages such as thinness, lightness, and low power consumption. A light-emitting element is provided which includes a first electrode, a second electrode, and an EL layer between the first electrode and the second electrode, in which the EL layer includes a layer containing a condensed aromatic compound or a condensed heteroaromatic compound, and a layer containing 2,9-bis(naphthalen-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBPhen) in contact with the layer containing the condensed aromatic compound or the condensed heteroaromatic compound.