Semiconducting Polymers for Air-Stable Organic Thin Film Transistors
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Solution Overview
Problem
Current silicon-based thin film transistors (TFTs) are costly and unsuitable for large-area electronic devices due to high manufacturing costs and complex fabrication processes, while n-type organic semiconductors with high electron mobility and air stability are rare, especially those that can be processed using solution-based methods.
Innovation Solution
Development of air-stable n-type and p-type semiconducting polymers with a specific molecular structure, such as Formula (I), which have a low Lowest Unoccupied Molecular Orbital (LUMO) energy level, enabling high mobility and stability, and can be processed using solution-based methods to form thin film transistors with improved performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If silicon-based TFT fabrication processes are used, then high switching speeds and high densities are achieved, but manufacturing costs increase and device flexibility is reduced
Solution Approach 1:
The patent changes the material parameter from silicon to organic semiconducting polymers, which enables processing at lower temperatures and via solution-based methods, thereby reducing manufacturing costs while maintaining acceptable switching speeds for display applications
Solution Approach 2:
The patent employs organic semiconducting polymers that can be processed using low-cost solution-based fabrication methods instead of expensive silicon manufacturing, making large-area electronic devices more cost-effective even if individual device lifetimes are shorter
2Speed
If silicon-based TFT fabrication processes are used, then high switching speeds are achieved, but device complexity and manufacturing process complexity increase
Solution Approach 1:
The patent replaces complex mechanical vacuum-based silicon fabrication processes with solution-based organic semiconductor processing, which uses simpler deposition techniques and lower temperatures, thereby reducing fabrication process complexity
Solution Approach 2:
The patent changes processing parameters from high-temperature vacuum processes to low-temperature solution processing, which simplifies the fabrication workflow and reduces equipment requirements
3Use of energy by moving object
If electron-withdrawing groups are applied to n-type organic semiconductors, then low LUMO energy levels are achieved, but air stability deteriorates
Solution Approach 1:
The patent uses composite molecular structures combining electron-withdrawing groups (for low LUMO) with sterically bulky protective groups (for air stability), creating a composite material that achieves both low LUMO energy levels and enhanced air stability
Solution Approach 2:
The patent applies electron-withdrawing groups at specific positions on the conjugated core while placing protective groups at other locations, creating local functional zones that separately handle electron transport and stability functions
4Ease of manufacture
If n-type organic semiconductors are developed for solution processing, then manufacturing costs are reduced, but air stability and mobility performance deteriorate
Solution Approach 1:
The patent develops composite molecular structures that integrate solution processability with air stability through careful molecular design, achieving both low-cost processing and reliable device performance
Solution Approach 2:
The patent optimizes molecular parameters including LUMO energy level, steric bulk, and solubility to achieve the right balance between solution processability and air stability
5Reliability
If high LUMO energy levels are used in n-type semiconductors, then air stability is improved, but electron mobility and device performance deteriorate
Solution Approach 1:
The patent creates local functional zones within the molecular structure where electron transport pathways maintain high mobility while protective groups provide air stability, allowing different regions to optimize for different functions
Data Source
AI summary
A semiconducting polymer of Formula (I):wherein X is independently selected from S, Se, O, and NR, wherein R is independently selected from hydrogen, alkyl, substituted alkyl, aryl, substituted aryl, heteroaryl, and —CN;Ar is independently a conjugated divalent moiety;a is an integer from 1 to about 10; andn is an integer from 2 to about 5,000.The resulting semiconducting polymer is suitable for use in organic thin film transistors.