OLED Emitter Layer Using Delayed Fluorescent and Fluorescent Compounds
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Solution Overview
Problem
Current organic light emitting diode (OLED) technologies face limitations in emitting efficiency and color purity due to the short lifespan of metal complex compounds used in phosphorescent materials, which restricts their commercialization and display performance.
Innovation Solution
An OLED structure is developed using a single emitting material layer or adjacent layers comprising a delayed fluorescent material and a fluorescent material, where the emitting material layer includes a first compound represented by Formula 1 and a second compound represented by Formula 2, optimizing the energy levels to enhance exciton transport and emission efficiency while improving color purity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If phosphorescent material (metal complex compound) is used to increase emitting efficiency, then emitting efficiency is improved, but lifespan is reduced
Solution Approach 1:
The patent changes the chemical composition parameters of the emitting material layer by using specific compounds (Formula 1 with a1-a3=0-4, n=1-5 and Formula 2 with b1-b4=0-5, b2=0-3, b4=0-4) and their weight ratios (first compound 1-50 wt%, second compound 1-10 wt%) to achieve both high emitting efficiency and long lifespan without metal complex compounds
Solution Approach 2:
The patent creates a composite emitting material layer combining two different organic compounds (first compound from Formula 1 and second compound from Formula 2) with complementary properties, where the first compound provides high efficiency and the second compound enhances stability and lifespan, achieving synergistic effects that overcome the limitations of single-material systems
2Device complexity
If fluorescent material is used to simplify the system, then device complexity is reduced, but emitting efficiency is reduced
Solution Approach 1:
The patent employs a composite material system with two specifically designed organic compounds that work together to achieve high emitting efficiency comparable to phosphorescent materials, while maintaining the simplicity of organic materials without requiring metal complexes or complex multi-layer structures
Solution Approach 2:
The patent optimizes the molecular structure parameters of the emitting materials (Formula 1 and Formula 2 with specific variable ranges) and their concentration parameters (weight ratios) to maximize emitting efficiency while keeping the material system relatively simple and free from metal complexes
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 increases the emitting efficiency and color purity of OLEDs by efficiently transporting excitons between the compounds, leading to improved performance and reduced driving voltage, overcoming the limitations of previous phosphorescent materials.
Implementation Method 1
efficiently transporting excitons between the compounds, leading to improved performance
Implementation Method 2
The OLED emits light by injecting electrons from a cathode as an electron injection electrode and holes from an anode as a hole injection electrode into an emitting material layer, combining the electrons with the holes, generating an exciton, and transforming the exciton from an excited state to a ground state
Data Source
AI summary
An organic light emitting diode includes a first electrode; a second electrode facing the first electrode; and an emitting material layer including a first compound and a second compound and positioned between the first and second electrodes. An energy level of the first compound and an energy level of the second compound satisfy a pre-determined condition. An organic light emitting device may include the organic light emitting diode.