OLED Exciton Blocking Layer for Efficiency and Stability
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Solution Overview
Problem
Current organic light emitting diodes face challenges in achieving low voltage, high efficiency, and long life span due to limitations in materials with poor thermal stability, electron and hole mobility, and chemical stability, particularly with materials like NPB and PEDOT:PSS, which hinder efficient exciton formation and light emission.
Innovation Solution
Incorporating specific organic material layers with compounds represented by Formulas 1 and 2, which act as exciton blocking layers, to confine excitons within the light emitting layer, enhancing light emitting efficiency and allowing for a simpler manufacturing process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If NPB is used as hole transport layer material, then the device can be manufactured, but the glass transition temperature is 100°C or lower causing poor thermal stability and difficulty in high current operation
Solution Approach 1:
The patent changes the chemical structure parameters of the hole transport material by introducing specific molecular structures (compounds of formulas 1 and 2 with aromatic hydrocarbon skeletons and electron-withdrawing groups) to achieve both high glass transition temperature and good electrochemical stability, resolving the contradiction between thermal stability and material performance
2Ease of manufacture
If PEDOT:PSS is used as hole transport material, then solution coating manufacturing is enabled, but the LUMO energy level is lower than light emitting layer material causing poor efficiency and short life span
Solution Approach 1:
The patent applies local quality by designing materials with specific functional groups positioned at particular locations in the molecular structure - electron-withdrawing groups at specific positions to raise LUMO energy level above the light emitting layer, while maintaining solution processability through appropriate molecular design
Solution Approach 2:
The patent uses composite material design by combining aromatic hydrocarbon skeleton with electron-withdrawing groups to create materials that simultaneously achieve high LUMO energy level, good hole transport capability, and solution processability
3Loss of energy
If organic material layers are added to block excitons, then light emitting efficiency is improved, but the device structure becomes more complex
Solution Approach 1:
The patent applies multi-functionality by designing the hole transport layer materials (compounds of formulas 1 and 2) to simultaneously perform hole transport and exciton blocking functions, eliminating the need for separate exciton blocking layers and reducing device structure complexity while maintaining high light emitting 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 solution results in organic light emitting diodes with improved light emitting efficiency, low voltage operation, and extended life span, while maintaining a straightforward and economical manufacturing process.
Implementation Method 1
An organic light emitting phenomenon is an example of a conversion of current into visible rays by an internal process of a specific organic molecule. When an organic material layer is interposed between an anode and a cathode, if voltage is applied between two electrodes, electrons and holes are injected from the cathode and the anode to the organic material layer. The electrons and the holes injected into the organic material layer are recombined to form an exciton, and the exciton is reduced to a bottom state to emit light.
Data Source
Figure 1
AI summary
The present invention relates to an organic light emitting diode and a method of manufacturing the same. An organic light emitting diode according to the present invention comprises an exciton blocking layer comprising a compound represented by Formula 1 to confine an exciton to a light emitting layer to prevent light emitting leakage, and thus there is an effect of implementing an organic electroluminescence diode having excellent light emitting efficiency. Accordingly, it is possible to implement an organic light emitting diode having a simple and economical manufacturing process, a low voltage, high efficiency, and a long life span as compared to the related art.