Aromatic Amic Acids for Stable OFETs

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Solution Overview

Problem

Current organic semiconductor materials for n-type field-effect transistors (OFETs) face challenges in achieving high mobility and stability, with existing n-channel materials exhibiting limited mobility and stability issues, particularly in air exposure, and requiring complex structural modifications for optimal performance.

Innovation Solution

Development of amic acid and amic ester compounds that can be thermally converted into arylene diimides, offering high mobility and stability through solid-state thermal dehydration imidization, allowing for easy deposition on various substrates without additional surface preparation and maintaining performance in air exposure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If existing n-channel organic semiconductor materials are used, then device operation is achieved, but mobility is limited and stability deteriorates in air exposure

Engineering Contradiction:

Improvestability in airVSAvoidmobility

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The patent modifies the chemical structure of n-channel semiconductor materials by introducing specific aromatic frameworks (naphthalene, perylene, anthracene) with electron-withdrawing groups and tailored substituents. This structural parameter change achieves both high mobility (>0.25 cm²/V·sec) and stability in air by optimizing electron affinity and molecular packing while resisting oxidation

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent develops composite molecular structures combining rigid aromatic cores with flexible side chains (alkyl, alkoxy, aryl groups). This composite approach enables simultaneous achievement of high charge carrier mobility through π-π stacking and environmental stability through steric protection and reduced reactivity

Inventive Principle:

Principle #40Composite materials

2Quantity of substance

If structural modifications are made to improve mobility, then performance increases, but device complexity increases

Engineering Contradiction:

ImprovemobilityVSAvoidstructural complexity

Core Design Contradiction:

Quantity of substanceVSDevice complexity

Solution Approach 1:

The patent segments the semiconductor molecule into distinct functional modules: a rigid aromatic core (naphthalene, perylene, or anthracene) for charge transport, electron-withdrawing groups (imide, anhydride) for electron affinity, and peripheral substituents for solubility and packing control. This modular segmentation achieves high mobility while maintaining synthetic accessibility

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies local quality modifications by introducing specific functional groups at strategic positions on the aromatic core. Electron-withdrawing groups are placed to optimize LUMO levels, while side chains are positioned to control molecular packing and solubility without disrupting the core π-system, achieving high mobility with controlled structural complexity

Inventive Principle:

Principle #3Local quality

3Quantity of substance

If high mobility materials are used, then electron transport improves, but ease of manufacture deteriorates due to deposition requirements

Engineering Contradiction:

Improveelectron mobilityVSAvoiddeposition process

Core Design Contradiction:

Quantity of substanceVSEase of manufacture

Solution Approach 1:

The patent uses soluble precursor compounds (amic acids, esters, or salts of aromatic tetracarboxylic acids) as intermediaries that can be deposited from solution onto substrates. These precursors are then thermally converted to the active high-mobility semiconductor material in situ, eliminating complex vacuum deposition processes while achieving >0.25 cm²/V·sec mobility

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces mechanical/physical vapor deposition methods with solution-based processing. The semiconductor material is delivered dissolved in solvent, applied by simple coating techniques, and converted to the active form by thermal treatment. This substitution maintains high mobility while dramatically improving ease of manufacture and scalability

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 amic acid and amic ester compounds provide thin films with field-effect electron mobility greater than 0.25 cm2/V·sec and on/off ratios of at least 10^4, achieving high performance and stability in n-type OFETs, even after repeated air exposure, with low-temperature processing and ease of deposition over large areas.

Implementation Method 1

amic acid and amic ester compounds that can be thermally converted into arylene diimides, offering high mobility and stability through solid-state thermal dehydration imidization

Methodology Applied

Scientific EffectThermal dehydration imidization:

Data Source

PatentUS8314265B2Aromatic amic acids or amic esters and compositions

Publication Date: 2012.11.20 EASTMAN KODAK CO

AI summary

Novel amic acids and amic esters can be thermally converted into corresponding arylene diimides. These amic acids and amic ester can be used as precursors to prepare semiconducting thin films that can be used in various articles including thin-film transistor devices that can be incorporated into a variety of electronic devices. In this manner, the arylene diimides need not be coated out of solvent in which they may be insoluble, but they can be generated in situ from a solvent-soluble, easily coated amic acid or amic ester.