Random Copolythiophene Semiconductors for Air-Stable Electronics
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Solution Overview
Problem
High-performance polythiophene semiconductors for electronics are not stable in air due to oxidative doping and have poor solution processability, requiring chlorinated solvents for optimal properties.
Innovation Solution
Development of random copolythiophenes with alkyl side chains that maintain high mobility and solubility in non-chlorinated solvents, allowing for ambient fabrication of thin-film transistors through spin-coating or ink-jet printing, by altering regioregularity via incorporation of 3-alkylthiophene monomers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If high-performance polythiophene semiconductors are used for electronic devices, then electronic properties are optimized, but stability in air deteriorates due to oxidative doping
Solution Approach 1:
The patent applies composite materials by creating copolythiophenes that combine two different monomer units: one providing high mobility (electron-donating group) and the other providing stability (electron-withdrawing group). This composite structure at the molecular level allows the material to simultaneously achieve both high electronic performance and air stability, resolving the contradiction between optimized electronic properties and stability in air.
2Reliability
If high-performance polythiophene semiconductors are used for electronic devices, then electronic properties are optimized, but solution processability worsens requiring chlorinated solvents
Solution Approach 1:
The patent applies parameter changes by modifying the chemical structure parameters of the polythiophene through copolymerization. By incorporating electron-withdrawing monomer units with appropriate side chains, the solubility parameter of the polymer is changed, enabling dissolution in non-chlorinated solvents while maintaining optimized electronic properties through the electron-donating units.
3Stability of the object's composition
If copolymerization with electron-withdrawing monomers is performed, then stability in air and solubility improve, but mobility may deteriorate
Solution Approach 1:
The patent applies local quality by creating a copolymer where different monomer units perform different functions at local levels. The electron-donating units are localized to provide high mobility in specific regions, while electron-withdrawing units are localized to provide stability and solubility in other regions. This spatial distribution of functional properties within the copolymer chain allows simultaneous optimization of all three properties.
Data Source
AI summary
A semiconducting copolythiophene composition that includes repeating units obtained from the copolymerization of compounds of Formula (2):and Formula (3):in which the copolythiophene has at least two repeating units (possessing side chains, such as alkyl side chains), which are arranged in manner such that the side chains on the polythiophene backbone are distributed non-uniformly, is described. Electronic devices incorporating such copolythiophene compositions are also described.