Water dispersible polythiophenes made with polymeric acid colloids
View Patent ↗Compositions are provided comprising aqueous dispersions of polythiophenes and colloid-forming polymeric acids. Films from invention compositions are useful as buffer layers in organic electronic devices, including electroluminescent devices, such as, for example, organic light emitting diodes (OLED) displays in combination with metal nanowires or carbon nanotubes in applications such as drain, source, or gate electrodes in thin film field effect transistors.
1. A buffer composition comprising an aqueous dispersion of a polydioxythiophene and at least one colloid-forming polymeric acid wherein said colloid-forming polymeric acid is a fluorinated polymeric sulfonic acid wherein said polydioxythiophene has the following structure:
Wherein R1 and R1′ form an alkylene chain having 1 to 4 carbon atoms, which is substituted by alkyl or aromatic groups having 1 to 12 carbon atoms, or R1 and R1′ form a 1,2-cyclohexylene radical, and n is greater than about 6.
2. A buffer composition according to claim 1 , wherein R 1 and R 1 ′ together form an alkylene chain having 1 to 4 carbon atoms.
3. A buffer composition according to claim 2 , wherein said polydioxythiophene comprises poly(3,4-ethylenedioxythiophene).
4. A buffer composition according to claim 1 , wherein said polymeric sulfonic acid is perfluorinated.
5. A buffer composition according to claim 1 , wherein said polymeric sulfonic acid is a perfluoroalkylenesulfonic acid.
6. A buffer composition according to claim 5 , wherein said polymeric sulfonic acid is perfluoroethylenesulfonic acid.
7. A buffer composition according to claim 1 , wherein the composition has a pH greater than about 3.
8. A buffer composition according to claim 1 , said composition further comprising an additional material selected from the group consisting of polymers, dyes, carbon nanotubes, metal nanowires, coating aids, organic and inorganic conductive inks and pastes, charge transport materials, crosslinking agents, and combinations thereof, wherein said colloid-forming polymeric acid is a fluorinated polymeric sulfonic acid.