Organic Semiconductor Liquid Composition for High Mobility Films

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Solution Overview

Problem

Current methods for preparing organic semiconductor films do not effectively achieve high mobility and durability, particularly in organic thin-film transistors, due to limitations in carrier transport and threshold voltage reduction.

Innovation Solution

An organic semiconductor liquid composition comprising a condensed polycyclic aromatic compound, a liquid crystal compound with a polymerizable group, and an organic insulating polymer, such as polyvinyl carboxylate or polyvinyl acetal, is used to form a laminated structure through coating, melting, and phase separation, enhancing carrier mobility and durability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional organic semiconductor compositions are used, then film formation is achieved, but carrier mobility remains low

Engineering Contradiction:
Improvecarrier mobilityVSAvoidfilm formation process
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent uses a composite material system consisting of small-molecule organic semiconductor, liquid crystal compound, and polymer compound. This composite approach allows the small-molecule semiconductor to provide high carrier mobility while the liquid crystal and polymer components facilitate easy film formation through solution processing. The liquid crystal compound acts as a solvent and structural director, enabling self-organization into high-mobility domains, while the polymer provides mechanical stability and processability.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent changes the physical and chemical parameters of the semiconductor system by introducing liquid crystal compounds with specific mesogenic groups and polymer compounds with appropriate solubility parameters. These parameter changes enable the formation of ordered molecular assemblies that maintain high carrier mobility while allowing solution-based processing. The solubility parameter matching between components is carefully controlled to achieve phase separation that benefits charge transport.

Inventive Principle:
Principle #35Parameter changes

2Ease of manufacture

If solution processing is used for film formation, then manufacturing simplicity is achieved, but film quality and durability are compromised

Engineering Contradiction:
Improvesolution processingVSAvoidfilm quality
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent exploits phase transitions of the liquid crystal compound to achieve high-quality film formation through solution processing. During film formation and subsequent heating, the liquid crystal undergoes phase transitions that drive self-organization of semiconductor molecules into ordered domains. This self-organization occurs spontaneously during the phase change process, eliminating the need for complex post-processing while achieving high film quality and durability.

Inventive Principle:
Principle #36Phase transitions

Solution Approach 2:

The liquid crystal compound performs preliminary action by pre-organizing semiconductor molecules into favorable configurations during film formation. The mesogenic structure of the liquid crystal pre-aligns the semiconductor molecules before final film solidification, creating a pre-formed template that ensures high-quality film structure without requiring additional processing steps. This preliminary organization is locked in during the phase transition from liquid crystal to solid state.

Inventive Principle:
Principle #10Preliminary action

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 approach results in an organic semiconductor film with improved mobility and reduced threshold voltage, enabling more efficient and stable organic thin-film transistor performance.

Implementation Method 1

a phase separation step of causing phase separation by cooling the melted film so as to form a laminated structure

Methodology Applied
Scientific EffectPhase separation: Phase Change

Implementation Method 2

an organic semiconductor liquid composition comprising the following three components: an organic semiconductor, a liquid crystal compound, and an organic insulating polymer

Methodology Applied
Scientific EffectDissolution: Solvation

Data Source

PatentEP3240056B1Organic semiconductor liquid composition and method of producing organic semiconductor element using said composition
Publication Date: 2020.04.22 FUJIFILM CORP
  • EP3240056B1 patent drawingFigure 1~2
  • EP3240056B1 patent drawingFigure 3~4
  • EP3240056B1 patent drawing

AI summary

An object of the present invention is to provide an organic semiconductor liquid composition making it possible to obtain an organic semiconductor film having high mobility, an organic semiconductor element prepared using the organic semiconductor liquid composition, and a method for preparing the organic semiconductor element. The organic semiconductor liquid composition of the present invention contains an organic semiconductor, a liquid crystal compound, and an organic insulating polymer. It is preferable that the organic insulating polymer includes a resin having a constitutional unit represented by Formula 1a and/or a constitutional unit represented by Formula 1b. In the formulae, R's each independently represents a linear or branched alkyl group having 1 to 20 carbon atoms.