ABSTRACT
Conjugated polymers have been the focus of numerous studies for their potential application in organic electronic devices, such as organic light-emitting diodes (OLEDs), organic photovoltaics (OPVs), and organic thin-film transistors (OTFTs). Trans-polyacetylene, the simplest of the conjugated polymers, is insoluble and intractable. Due to the insolubility of unsubstituted conjugated polymers, several synthetic methods were developed to produce soluble precursor polymers, which upon treatment provide the desired properties in the final product. Unsubstituted conjugated polymers are insoluble, but derivatives modified with long alkyl or alkoxy chains can be solution-processed for incorporation in devices. Altering the structure of conjugated polymers to improve solubility can also be achieved by using bulky substituents. The molecular weight of conjugated polymers might be the most readily understood factor effecting solubility. Both the choice of polymerization solvent and the device fabrication solvent can influence device performance. The use of sulfonium salts in the Wessling–Zimmerman route affords water-soluble precursors.
