Solid-State Organic Solvent Composition for OE Device Film Formation

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Solution Overview

Problem

Existing methods for preparing organic electronic (OE) devices, such as OPV cells and OLEDs, face challenges with low solubility of organic semiconducting compounds, requiring high amounts of solvents and surfactants, which affect film quality and multilayer device production, and struggle with achieving high efficiency, long lifetime, and low sensitivity to oxidation and water.

Innovation Solution

A composition that is solid at 50°C and fluid at higher temperatures, using specific solvents and additives to achieve optimal viscosity and surface tension, allowing for improved film formation and multilayer device printing, with a process involving deposition and solvent removal to form high-quality OE devices.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If high amounts of solvents are used to dissolve organic semiconducting compounds, then solubility is improved, but film quality deteriorates due to solvent de-wetting and reduced levelness

Engineering Contradiction:
ImprovesolubilityVSAvoidfilm levelness
Core Design Contradiction:
Stability of the object's compositionVSManufacturing precision

Solution Approach 1:

The patent changes the physical state parameter of the solvent from liquid to solid (using solvents with melting points above room temperature). This allows the composition to be applied as a solid that melts during processing, fundamentally altering how the solvent behaves during film formation and eliminating de-wetting issues while maintaining solubility.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent utilizes phase transition of the solvent by selecting solids that melt at processing temperatures. The solid solvent provides structural support during application, then transitions to liquid phase during heating to enable proper film formation and leveling, combining the benefits of both solid and liquid states.

Inventive Principle:
Principle #36Phase transitions

2Manufacturing precision

If surfactants are used to reduce solvent de-wetting and increase film levelness, then film quality is improved, but the amount of surfactant needed is high in relation to OSC material

Engineering Contradiction:
Improvefilm levelnessVSAvoidsurfactant amount
Core Design Contradiction:
Manufacturing precisionVSQuantity of substance

Solution Approach 1:

By changing the solvent from liquid to solid state, the patent eliminates the need for surfactants to control de-wetting. The solid solvent inherently prevents de-wetting through its structural properties, and upon melting provides controlled fluidity for film leveling without requiring additional surfactant additives.

Inventive Principle:
Principle #35Parameter changes

3Ease of operation

If conventional liquid solvents are used, then ease of application is improved, but multilayer device production becomes difficult due to solvent dissolution of existing layers

Engineering Contradiction:
Improveapplication easeVSAvoidmultilayer production
Core Design Contradiction:
Ease of operationVSEase of manufacture

Solution Approach 1:

The patent uses solid solvents with high melting points that do not dissolve organic semiconducting compounds at room temperature. This allows subsequent layers to be applied without the new solvent dissolving previously deposited layers, enabling straightforward multilayer device fabrication while maintaining ease of application through the solid-state composition.

Inventive Principle:
Principle #35Parameter changes

4Ease of operation

If the composition is fluid at room temperature, then ease of deposition is improved, but film homogeneity deteriorates due to poor leveling without high amounts of wetting agents

Engineering Contradiction:
Improvedeposition easeVSAvoidfilm homogeneity
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The patent applies the composition as a solid that melts during processing. The solid state provides excellent leveling and homogeneity during deposition, then the controlled melting transition enables proper flow and film formation, achieving both high homogeneity and ease of deposition without requiring excessive wetting agents.

Inventive Principle:
Principle #36Phase transitions

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 enhances the efficiency, lifetime, and homogeneity of OE devices, particularly in OPV cells and OLEDs, by reducing solvent usage and improving film quality, enabling better multilayer device production.

Implementation Method 1

a composition being solid at a temperature of 50°C and fluid at a higher temperature

Methodology Applied
Scientific EffectPhase transition: Phase Change

Implementation Method 2

removing the solvent(s)

Methodology Applied
Scientific EffectEvaporation: Evaporation

Data Source

PatentEP2559079B1Composition and method for preparation of organic electronic devices
Publication Date: 2020.04.01 MERCK PATENT GMBH
  • EP2559079B1 patent drawingFigure 1a~2
  • EP2559079B1 patent drawingFigure 3~5
  • EP2559079B1 patent drawing

AI summary

The present invention relates to novel compositions comprising an organic semiconductor (OSC) and one or more organic solvents. The composition is solid at a temperature of 25°C and fluid at a higher temperature and the boiling point of the solvent is at most 400°C. 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 OLED devices, to methods for preparing OE devices using the novel compositions, and to OE devices, OLED devices and OPV cells prepared from such methods and compositions.