Multistack Organic Emission Layers for Low-Voltage OLED Efficiency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing organic electronic devices face challenges in achieving low driving voltage, high efficiency, high color purity, and increased lifespan, particularly in large-area portable displays where efficient power consumption is crucial.
Innovation Solution
The organic electronic device comprises a first electrode, a second electrode, and an organic material layer with a multistack structure, including a first stack with a hole transport region, an emission layer, and an electron transport region. The hole transport region includes a hole transport layer and an auxiliary emission layer, with specific compounds and doping materials used to optimize charge balance and thermal stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the organic material layer is improved to increase efficiency, then luminous efficiency is improved, but driving voltage may increase and lifespan may decrease due to Joule heating
Solution Approach 1:
The patent modifies the chemical structure of organic compounds by changing parameters such as introducing specific heteroatoms (B, Si, Ge, Sn), adjusting molecular weight (200-500 Da), and modifying functional groups to achieve optimal balance between efficiency and thermal stability. This allows high luminous efficiency while maintaining low driving voltage and preventing crystallization.
Solution Approach 2:
The patent uses composite organic materials combining multiple elements (B, Si, Ge, Sn) with specific functional groups to create materials that simultaneously provide high efficiency and thermal stability. The composite structure prevents crystallization while maintaining charge balance and reducing Joule heating effects.
2Area of stationary object
If display size is increased to create large-area displays, then area is improved, but power consumption increases and efficiency decreases
Solution Approach 1:
The patent divides the organic material layer into multiple stacks (first stack, second stack, third stack) with distinct functional layers. This segmentation allows each stack to be optimized for specific functions (hole transport, emission, electron transport), improving overall efficiency and reducing power consumption in large-area displays.
Solution Approach 2:
Different regions of the organic material layer are assigned different materials with specific properties optimized for their function. The hole transport region uses compounds with high hole mobility, the emission layer uses compounds with optimal energy levels, and the electron transport region uses compounds with high electron mobility, achieving local optimization that reduces overall power consumption.
3Reliability
If organic materials are optimized to reduce Joule heating, then lifespan is improved, but achieving charge balance and thermal stability simultaneously is difficult
Solution Approach 1:
The patent establishes specific parameter ranges for organic compounds: molecular weight of 200-500 Da, specific heteroatom content, and defined functional groups. These parameter specifications simplify the selection process while ensuring both charge balance and thermal stability are achieved, reducing the complexity of material optimization.
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
This configuration results in an organic electronic device with enhanced luminous efficiency, low driving voltage, high thermal resistance, improved color purity, and extended lifespan.
Implementation Method 1
In general, organic electroluminescence refers to a phenomenon in which electrical energy is converted into light energy using an organic material.
Implementation Method 2
An increase in efficiency leads to a relative decrease in driving voltage, by which the crystallization of the organic material due to Joule heating during driving may be reduced
Data Source
AI summary
Embodiments of the present invention relate to an organic electronic device capable of ensuring high luminous efficiency, low driving voltage and high heat resistance, and improving color purity or lifespan.