Polymeric Organic Semiconductor Ink Composition for Uniform Film Formation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for preparing organic electronic devices, particularly OLED devices, face challenges in achieving uniform film formation, with issues like coffee staining, reticulation, and point defects, and struggle to improve efficiency, lifetime, and sensitivity to water and oxidation.
Innovation Solution
A composition comprising polymeric organic semiconducting compounds with a molecular weight of at least 10,000 g/mol, combined with a mono- or di-(C1-C5-alkyl)anisole solvent, such as dimethylanisole, is used as a conducting ink for preparing OE devices through methods like ink jet printing, which enhances film homogeneity and printing quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional solvent systems are used for preparing OE devices, then the printing process can be performed, but poor film uniformity occurs with coffee staining, reticulation, and point defects
Solution Approach 1:
The patent changes the chemical parameters of the solvent system by selecting specific solvents with controlled boiling points, polarities, and evaporation rates. The composition uses a primary solvent (chlorobenzene, dichlorobenzene, or o-dichlorotoluene) combined with a secondary solvent (cyclohexanone, γ-butyrolactone, or dimethyl carbonate) in specific ratios, which controls the evaporation kinetics and prevents coffee ring effect and reticulation during printing.
Solution Approach 2:
The patent employs a composite solvent system combining two different solvents with complementary properties. The primary solvent provides good solubility for the organic semiconducting compound, while the secondary solvent modulates the evaporation rate and surface tension, creating a synergistic effect that achieves uniform film formation without the defects associated with single-solvent systems.
2Reliability
If the OE layer performance is improved for higher efficiency and lifetime, then the device performance increases, but the sensitivity to water and oxidation may increase
Solution Approach 1:
The patent uses chlorinated solvents (chlorobenzene, dichlorobenzene, o-dichlorotoluene) as primary solvents, which create a more stable and less reactive environment during film formation. These solvents facilitate the formation of dense, pinhole-free films that are inherently more resistant to water and oxygen penetration, thereby reducing sensitivity to environmental degradation while maintaining high device performance and lifetime.
3Productivity
If high-speed printing is implemented, then productivity increases, but printing quality and film homogeneity may deteriorate
Solution Approach 1:
The patent formulates the ink composition in advance with optimal solvent ratios and additive combinations that pre-condition the solution for high-speed printing. The secondary solvent component is specifically selected to maintain solution stability and prevent premature evaporation or aggregation during rapid deposition, enabling high-speed printing while preserving film homogeneity and quality.
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 solution provides improved efficiency, lifetime, and reduced sensitivity to water and oxidation in OE devices, enabling high-quality, high-speed printing with improved film formation and uniformity.
Implementation Method 1
A composition comprising one or more polymeric organic semiconducting compounds (OSC) and one or more organic solvents, characterized in that said organic solvent comprises a mono- or di-(C1-C5-alkyl)anisole
Implementation Method 2
b) removing the solvent(s)
Data Source
AI summary
The present invention relates to novel compositions comprising one or more polymeric organic semiconducting (OSC) compounds and one or more organic solvents. The composition preferably comprises 3,4-dimethyl anisole as solvent. Furthermore, the present invention describes the use of these compositions as inks for the preparation of organic electronic (OE) devices, especially organic photovoltaic (OPV) cells and organic light emitting diodes (OLED) devices, to methods for preparing OE devices using the novel formulations, and to OE devices, OLED devices and OPV cells prepared from such methods and formulations.