Substituted Benzodithiophene Polymers for Organic Electronics
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing organic electronic devices, such as OLEDs, face challenges with high operating voltage, inadequate efficiency, and short lifetime, particularly when using polymer layers with conjugated polymers that often disrupt conjugation or require charge-transfer complexes.
Innovation Solution
Polymers and polymer blends containing specific structural units, such as those described by formula (I), which reduce operating voltage, enhance efficiency, and improve stability by optimizing charge transport properties and molecular structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conjugated polymers are used in organic electronic devices, then electron-transport properties are improved, but operating voltage becomes too high and lifetime is reduced
Solution Approach 1:
The patent changes the chemical structure parameters of the polymer by introducing specific substituted benzodithiophene units with electron-donating or electron-withdrawing groups. This modifies the HOMO-LUMO energy levels and band gap of the polymer, enabling better energy alignment with electrodes and charge-transport layers, thereby reducing operating voltage while maintaining electron-transport properties
Solution Approach 2:
The patent creates composite polymer structures by combining benzodithiophene core units with various substituent groups (alkyl, alkoxy, aryl, heteroaryl groups). These composite structures achieve synergistic effects where the core provides electron-transport pathways while the substituents tune energy levels and improve molecular packing, resolving the contradiction between transport properties and operating voltage
2Reliability
If conjugated polymers are used in organic electronic devices, then electron-transport properties are improved, but device lifetime is reduced
Solution Approach 1:
The patent modifies the chemical stability parameters of the polymer by selecting specific substituent groups that enhance resistance to oxidation and degradation. Electron-donating groups stabilize the polymer backbone against electrophilic attack, while the overall molecular structure is designed to resist photo-oxidation and thermal degradation, thereby extending device lifetime while maintaining transport properties
Solution Approach 2:
The patent employs solution-processable polymer materials that can be deposited as stable films, replacing less stable small-molecule organic semiconductors. The polymeric nature provides inherent stability against sublimation and phase separation, extending device operational lifetime
3Reliability
If hole transporters based on triarylamine are incorporated into conjugated polymers, then charge transport is improved, but conjugation is interrupted and efficiency decreases
Solution Approach 1:
The patent introduces hole-transporting substituents at specific positions on the benzodithiophene core while maintaining the conjugation of the main polymer backbone. The substituents provide localized hole-transport functionality without interrupting the delocalized electron system along the backbone, thus maintaining both charge transport and efficiency
Solution Approach 2:
The patent designs multi-functional benzodithiophene units that simultaneously provide electron-transport pathways through the conjugated backbone and hole-transport capability through incorporated substituents. This universal unit performs multiple charge transport functions without requiring separate layers or materials, maintaining device efficiency
Data Source
AI summary
The present invention relates to polymers containing substituted benzodithiophene units and to blends which comprise the polymers according to the invention. The invention is also directed to the use of the polymers and blends according to the invention in organic electronic devices and to these devices themselves.