Organic Electroluminescent Element Dark Spot Inhibition
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Organic electroluminescent elements experience the generation of dark spots during driving, which is a performance issue that existing materials fail to adequately address.
Innovation Solution
Incorporating a specific compound with a structure represented by general formula (I) into the organic electroluminescent element, where Q is an aromatic fused hydrocarbon ring or heterocycle, and Ar is an arylene or heteroarylene group, linked by a divalent group, to inhibit dark spot formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If conventional compounds with aromatic fused rings are used as light emitting materials, then the organic electroluminescent element can achieve high luminance at low voltage, but dark spots are generated during driving
Solution Approach 1:
The patent changes the molecular structure parameters of the light emitting material by introducing specific fused ring systems (pyrene, triphenylene, coronene) with defined carbon atom counts (10-30 for hydrocarbon rings, 8-30 for heterocycles). This structural parameter modification prevents dark spot generation while maintaining the electroluminescence performance of high luminance at low voltage operation.
Solution Approach 2:
The invention uses composite molecular structures combining core fused ring systems with aromatic substituent groups linked through linking groups. These composite structures integrate multiple functional moieties (electron-transporting groups, hole-transporting groups, light-emitting chromophores) into a single molecule, achieving both high luminance and reliability by preventing the dark spot defect mechanism.
2Ease of manufacture
If simple fused ring structures are used, then the synthesis is easier, but the element exhibits poor durability and dark spot formation
Solution Approach 1:
The patent modifies the molecular parameters by specifying fused ring systems with 10-30 carbon atoms for hydrocarbons and 8-30 for heterocycles, with substituents containing 6-30 carbon atoms. These parameter ranges balance synthetic accessibility with improved molecular stability that prevents dark spot formation, thereby extending element operational lifetime while maintaining reasonable synthesis complexity.
3Device complexity
If compounds with fewer aromatic groups per core are used, then the molecular complexity is reduced, but dark spots are generated during operation
Solution Approach 1:
The patent establishes specific parameter ranges for molecular complexity: core fused rings with defined carbon counts, substituents with 6-30 carbon atoms, and linking groups with 1-3 atoms. These parameter specifications create an optimal balance where the molecular structure is complex enough to prevent dark spot formation through improved charge distribution and exciton management, but not so complex as to make synthesis prohibitively difficult.
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 use of this compound effectively prevents the generation of dark spots during driving, enhancing the performance and reliability of the organic electroluminescent element, even at high dew point temperatures.
Implementation Method 1
utilize, for light emitting, energy of the exciton generated as a result of recombination of electrons injected from a cathode and holes injected from an anode in the organic layer
Data Source
AI summary
An organic electroluminescent element including a substrate, a pair of electrodes including an anode and a cathode, disposed on the substrate, and at least one organic layer including a light emitting layer, disposed between the electrodes, in which at least one kind of compound represented by the following general formula is contained in any layer of the at least one organic layer, is an organic electroluminescent element, in which the generation of dark spots during driving is inhibited: