OLED Emission-Auxiliary Layer for Charge Balance and Color Purity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current organic electric elements face challenges with efficiency, lifespan, and color purity due to charge imbalance and metal oxide penetration, requiring the development of materials with optimal energy levels and high T1 values, as well as heat resistance to improve performance.
Innovation Solution
The use of specific compounds in the organic electric element's emission-auxiliary and hole transport layers, represented by Formulas 1 and 2, which enhance luminous efficiency, reduce driving voltage, and improve heat resistance and color purity by optimizing energy levels and material properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a hole transport layer material with low HOMO value is used, then charge transport is improved, but T1 value decreases causing exciton transfer to hole transport layer, reducing color purity and efficiency
Solution Approach 1:
An emission-auxiliary layer is introduced as an intermediary between the hole transport layer and light emitting layer. This layer has a HOMO level positioned between the HOMO levels of the hole transport layer and light emitting layer, acting as an energy barrier that prevents exciton transfer from the light emitting layer to the hole transport layer, thereby maintaining color purity and luminous efficiency while allowing efficient charge transport
2Productivity
If efficiency is increased by improving organic material layer, then driving voltage is lowered and life span increases, but emission problems require additional emission-auxiliary layers for each light emitting layer color
Solution Approach 1:
The patent develops universal emission-auxiliary layer materials that can be applied across different light emitting layer compositions (red, green, blue). These materials possess inherent properties (high T1 value, appropriate HOMO level positioning) that make them broadly applicable to various OLED configurations, reducing the need to develop separate emission-auxiliary layers for each color and simplifying the overall device structure
3Ease of manufacture
If hole injection layer material has low glass transition temperature, then ease of manufacture is improved, but film surface uniformity collapses during operation, shortening life span
Solution Approach 1:
The patent modifies the glass transition temperature parameter of hole injection layer materials to be sufficiently high (above the operating temperature range of the OLED). This parameter change ensures that the hole injection layer maintains its structural integrity and film surface uniformity during device operation, preventing collapse and extending element life span while still allowing for effective manufacturing
4Device complexity
If metal oxides penetrate from anode electrode into organic layer, then device structure is simplified, but life span is shortened due to material degradation
Solution Approach 1:
The hole injection layer serves as an intermediary barrier between the anode electrode (containing metal oxides) and the organic layers. This layer is designed with properties that prevent penetration and diffusion of metal oxides from the anode into the sensitive organic materials, thereby protecting the organic layers from degradation and extending element life span without adding significant structural 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 organic electric element achieves high luminous efficiency, low driving voltage, and extended lifespan with improved color purity and heat resistance, addressing the limitations of existing materials.
Implementation Method 1
an organic light emitting phenomenon refers to a phenomenon in which electric energy is converted into light energy by means of an organic material
Implementation Method 2
an electron transferred from an electron transport layer to a light emitting layer and a hole transferred from a hole transport layer to the light emitting layer are recombined to form an exciton
Implementation Method 3
the crystallization of an organic material due to Joule heating generated during operation is reduced as driving voltage is lowered
Data Source
AI summary
A compound represented by Formula 1. An organic electric element includes a first electrode, a second electrode, and an organic material layer including the compound of Formula 1. The organic material layer include a light emitting layer, a hole transport layer including a compound represented by Formula 2, and an emission-auxiliary layer including the compound represented by Formula 1. When the organic electric element includes the compound in the organic material layer, luminous efficiency, color purity, and life span can be improved.