OLED Electron Transport Layer Structure for Longer Service Life
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Solution Overview
Problem
There is a continuous need for developing new materials to improve the efficiency, stability, and service life of organic light emitting devices.
Innovation Solution
The organic light emitting device incorporates a first organic material layer acting as a hole blocking layer and a second organic material layer that can function as an electron injection and transport layer, utilizing compounds of specific Formulae 1, 2, and 3, which include a monocyclic heteroaryl group bonded to a fluorene core and aromatic hydrocarbon groups substituted with a monocyclic heteroaryl group and a nitrile group, respectively, to enhance electron injection and transport capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If conventional organic material layers are used in the organic light emitting device, then the device structure is simple, but the service life and efficiency characteristics are insufficient
Solution Approach 1:
The patent divides the electron transport layer into two distinct layers: a first electron transport layer in contact with the light emitting layer, and a second electron transport layer in contact with the first electron transport layer. Each layer uses different organic compounds with specific molecular structures (Formulae 1-6) optimized for their respective positions, thereby extending device service life while managing structural complexity through functional segmentation.
Solution Approach 2:
The patent employs composite material strategies by combining specific organic compounds with defined molecular structures (Formulae 1-6) in the electron transport layers. These composite organic materials are designed with particular heteroaryl groups and substituents to achieve synergistic effects that improve service life and efficiency characteristics beyond what single materials can provide.
2Productivity
If conventional organic materials are used, then the manufacturing process is simple, but the light emitting efficiency and driving voltage characteristics are insufficient
Solution Approach 1:
The patent applies local quality by assigning specific molecular structures (Formulae 1-6) to different regions of the electron transport layers. The first electron transport layer uses compounds optimized for interfacing with the light emitting layer, while the second layer uses compounds optimized for electron injection from the electrode, thereby improving light emitting efficiency and driving voltage characteristics through location-specific material optimization.
Solution Approach 2:
The patent utilizes parameter changes by modifying molecular structures (Formulae 1-6) of organic compounds in the electron transport layers. Specific structural parameters such as heteroaryl groups, substituents, and molecular configurations are adjusted to optimize electron transport properties, thereby improving light emitting efficiency and electrical characteristics while maintaining manufacturability.
3Power
If excessive electron injection occurs, then the device may operate at lower voltage, but the service life and stability deteriorate
Solution Approach 1:
The patent implements beforehand cushioning by designing the electron transport layers with specific organic compounds (Formulae 1-6) that prevent excessive electron injection before it can cause damage. The molecular structures are engineered to regulate electron flow and protect the light emitting layer from degradation, thereby extending service life while maintaining acceptable driving voltage levels.
Solution Approach 2:
The patent uses intermediary materials in the electron transport layers (Formulae 1-6) that mediate between the electrode and the light emitting layer. These intermediary organic compounds control electron injection rates, preventing excessive electron flow that would degrade the light emitting layer, thereby protecting device reliability while managing operating voltage.
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 improves the driving voltage, light emitting efficiency, and service life characteristics of the organic light emitting device by reducing excessive electron injection and maintaining structural integrity through appropriate orbital distributions and heat stability.
Implementation Method 1
An organic light emitting phenomenon refers to a phenomenon in which electric energy is converted into light energy by using an organic material
Data Source
AI summary
An organic light emitting device including: a positive electrode; a negative electrode facing the positive electrode; a light emitting layer between the positive electrode and the negative electrode; a first organic material layer comprising a compound of Formula 1 provided between the negative electrode and the light emitting layer; and a second organic material layer comprising at least one compound of Formulae 2 or 3 provided between the negative electrode and the first organic material layer: wherein the first organic layerat least one of X1 to X3 is N, at least one of X4 to X6 is N, at least one of X7 to X9 is N, and at least one of X10 to X12 is N, and each remaining one is CH;R1 and R2 are each independently a substituted or unsubstituted alkyl or aryl group, or together form a substituted or unsubstituted hydrocarbon ring;each of L1, L2, L3 and L5 independently is a direct bond or a substituted or unsubstituted arylene group;L4 is a divalent or trivalent aromatic hydrocarbon group;Ar1 and Ar2 are each independently a substituted or unsubstituted aryl or heteroaryl group;Ar3 to Ar8 are each independently a substituted or unsubstituted aryl group; andn1 is 1 or 2.