Stilbene Derivatives for Blue Emissive Light-Emitters
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Solution Overview
Problem
Current blue light-emitting elements lack sufficient reliability and color purity, hindering the development of high-quality full-color light-emitting devices.
Innovation Solution
Development of novel stilbene derivatives with specific structural formulas, such as those represented by general formulas (1) to (9), which are used in light-emitting layers between electrodes to enhance color purity and efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional materials are used for blue light-emitting elements, then device complexity is reduced, but color purity and reliability are insufficient
Solution Approach 1:
The patent applies parameter changes by systematically varying the molecular structure of stilbene derivatives, specifically modifying the aryl groups (Ar1 and Ar2) and their substituents to optimize emission properties. By changing parameters such as the type of aryl group (phenyl, naphthyl, carbazolyl), the position of substituents (ortho, meta, para), and the nature of substituents (diphenylamino, carbazolyl, triphenylamine groups), the patent achieves both improved color purity and reliability while maintaining reasonable device complexity.
Solution Approach 2:
The patent employs composite materials by creating complex stilbene derivative molecules that combine multiple functional groups and aryl moieties. These composite molecular structures, such as those with diarylamino groups combined with carbazolyl or triphenylamine groups, enable simultaneous achievement of high color purity and reliability that cannot be obtained with simpler single-function molecules.
2Reliability
If conventional materials are used for blue light-emitting elements, then manufacturing process is simpler, but color purity is insufficient
Solution Approach 1:
The patent uses parameter changes to optimize color purity by carefully selecting and positioning substituents on the stilbene core structure. By varying parameters such as the type of aryl group (6-25 carbon atoms), substituent positions (ortho, meta, para relative to the double bond), and substituent types (diphenylamino, carbazolyl, triphenylamine), the patent achieves excellent color purity while maintaining synthetic feasibility through established organic chemistry methods.
Solution Approach 2:
The patent applies local quality by introducing specific functional groups at specific positions on the stilbene molecule. The diarylamino group (NAr1Ar2) and other substituents are placed at specific locations (ortho, meta, or para positions relative to the double bond) to locally enhance electron distribution and optimize emission properties, thereby achieving high color purity without requiring complete redesign of the entire molecular structure.
3Adaptability or versatility
If blue emissive light-emitting element is developed, then full-color light-emitting device can be manufactured, but color purity and reliability are insufficient
Solution Approach 1:
The patent applies parameter changes by systematically modifying the molecular structure of stilbene derivatives to achieve the specific emission characteristics required for full-color displays. By varying the aryl groups (Ar1 and Ar2 with 6-25 carbon atoms), the type of substituents (diphenylamino, carbazolyl, triphenylamine), and their positions, the patent optimizes the blue emission properties to meet the stringent color purity requirements for RGB display applications, thereby enabling reliable full-color light-emitting devices.
Solution Approach 2:
The patent uses local quality by introducing electron-donating diarylamino groups (NAr1Ar2) and other functional groups at specific positions on the stilbene core. These local modifications create the appropriate electron distribution and HOMO-LUMO energy levels necessary for high-color-purity blue emission, making the material suitable for integration into full-color display devices alongside red and green emitters.
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 novel stilbene derivatives enable the creation of blue-emissive light-emitting elements with excellent color purity, leading to improved color reproducibility in display devices and electronic devices.
Implementation Method 1
Light emission from a singlet excited state is referred to as fluorescence... The present invention provides novel stilbene derivatives... which can provide excellent color purity of blue
Implementation Method 2
when voltage is applied between the pair of electrodes, holes injected from the anode and electrons injected from the cathode recombine in a light-emitting layer including a luminescent substance, whereby a molecular exciton is formed, and energy is released when the molecular exciton relaxes to a ground state. Thus, light is emitted.
Data Source
AI summary
A novel stilbene derivative is provided with motivation of providing a blue emissive material showing excellent color purity. The use of the stilbene derivative of the present invention allows the fabrication of a blue-emissive light-emitting element with excellent color purity. The invention also includes an electronic device equipped with a display portion in which the stilbene derivative is employed. The stilbene derivative of the present invention is represented by formula (1), in which Ar1 and Ar2 may form a 5-membered ring by being directly bonded to each other. In formula (1), A11 represents any one of substituents represented by general formulas (1-1) to (1-3). The variables shown in formula (1) and (1-1) to (1-3) are as defined in the specification.