Solutions and dispersions of organic semiconductors
View Patent ↗The present invention relates to solutions and/or dispersions of organic semiconductors in a solvent mixture of at least two different organic solvents, characterized in that A. Each of the solvents on its own has a boiling point of below 200° C. and a melting point of 15° C. or less, B. at least one of the solvents has a boiling point in the range from greater than 140 to less than 200° C., C. the solvents used have no benzylic CH 2 or CH groups, D. the solvents used are not benzene derivatives containing tert-butyl substituents or more than two methyl substituents, and their use in printing processes for producing layers of organic semiconductors, especially for the electronics industry.
1. A solution or dispersion which comprises an undoped polymeric organic semiconductor in a solvent mixture of at least two different organic solvents, wherein
A. Each of the solvents on its own has a boiling point of at least 100° C. and below 200° C. and a melting point of 15° C. or less,
B. at least one of the solvents has a boiling point in the range from greater than 140 to less than 200° C.,
C. the solvents used have no benzylic CH 2 or CH groups,
D. the solvents used are not benzene derivatives containing tert-butyl substituents or more than two methyl substituents and
wherein the solution or the dispersion comprises only solvents having a boiling point of at least 100° C. and wherein said polymeric organic semiconductor used is a substituted, soluble copolymer comprising structural units of at least two of the polymer classes selected from the group consisting of a soluble poly-p-arylene-vinylene (PAV), polyfluorenes (PFs), a soluble polyspirobifluorene (PSF), a soluble poly-para-phenylene (PPP), substituted, soluble polythiophene (PT), a substituted, soluble polypyridine (Ppy) and a substituted, soluble polypyrrole.
2. The solution or dispersion as claimed in 1 , wherein the solvents used have no chloroform or tetrachloromethane.
3. A solution or dispersion as claimed in claim 1 , wherein said solution or dispersion is a solution.
4. A solution or dispersion as claimed in claim 1 , wherein said solution or dispersion is a dispersion.
5. A solution or dispersion as claimed in claim 1 , wherein the organic semiconductor is a polymeric organic semiconductor.
6. A solution or dispersion as claimed in claim 5 , wherein said solution or dispersion is a solution.
7. A solution as claimed in claim 6 , wherein the polymeric organic semiconductor used is a soluble poly-p-arylene-vinylene (PAV).
8. A solution as claimed in claim 6 , wherein the polymeric organic semiconductor used is a soluble polyfluorene (PF).
9. A solution as claimed in claim 6 , wherein the polymeric organic semiconductor used is a soluble polyspirobifluorene (PSF).
10. A solution as claimed in claim 6 , wherein the polymeric organic semiconductor used is a soluble poly-para-phenylene (PPP).
11. A solution as claimed in claim 6 , wherein the polymeric organic semiconductor used is a substituted, soluble polythiophene (PT).
12. A solution as claimed in claim 6 , wherein the polymeric organic semiconductor used is a substituted, soluble polypyridine (PPy).
13. A solution as claimed in claim 6 , wherein the polymeric organic semiconductor used is a substituted, soluble polypyrrole.
14. A solution as claimed in claim 6 , wherein the polymeric organic semiconductor used is a substituted, soluble copolymer comprising structural units of at least two of the polymer classes selected from the group consisting of a soluble poly-p-arylene-vinylene (PAV), a soluble polyspirobifluorene (PSF), a soluble poly-para-phenylene (PPP), substituted, soluble polythiophene (PT), a substituted, soluble polypyridine (Ppy) and a substituted, soluble polypyrrole.
15. A solution as claimed in claim 6 , wherein the polymeric organic semiconductor used is a substituted or unsubstituted polyvinylcarbazole or a substituted or unsubstituted triarylamine polymer.
16. a solution or dispersion as claimed in claim 1 , wherein the solution or the dispersion contains from 0.26 to 10% by weight of the organic semiconductor.
17. A solution or dispersion as claimed in claim 1 , wherein the solution or the dispersion comprises solvents having different boiling points.
18. A solution or dispersion as claimed in claim 1 , wherein the solution or the dispersion comprises one or more solvents selected from the group consisting of o-xylene, 2,6-lutidine, 2-fluoro-m-xylene, 3-fluoro-o-xylene, 2-chlorobenzotrifluoride, dimethylformamide, 2-chloro-6-fluorotoluene, 2-fluoroanisole, anisole, 2,3-dimethylpyrazine, 4-fluoroanisole, 3-fluoroanisole, 3-trifluoromethylanisole, 2-methylanisole, phenetole, 4-methylanisole, 3-methylanisole, 4-fluoro-3-methylanisole, 2-fluorobenzonitrile, 4-fluoroveratrole, 2,6-dimethylanisole, 3-fluorobenzonitrile, 2,6-dimethylanisole, 2,4-dimethylanisole, benzonitrile, 3,5-dimethylanisole, N,N-dimethylaniline, 1-fluoro-3,5-dimethoxybenzene and N-methylpyrrolidinone.
19. A solution or dispersion as claimed in claim 18 , wherein the solution or the dispersion further comprises one or more solvents selected from the group consisting of 3-fluorobenzotrifluoride, benzotrifluoride, dioxane, trifluoromethoxybenzene, 4-fluorobenzotrifluoride, 3-fluoropyridine, toluene, 2-fluorotoluene, 2-fluorobenzotrifluoride, 3-fluorotoluene, pyridine, 4-fluorotoluene, 2,5-difluoro-toluene, 1-chloro-2,4-difluorobenzene, 2-fluoropyridine, 3-chlorofluorobenzene, 1-chloro-2,5-difluprobenzene, 4-chlorofluorobenzene, chlorobenzene, 2-chlorofluorobenzene, p-xylene and m-xylene.
20. A solution or dispersion as claimed in claim 1 , wherein the solution or the dispersion comprises at least three different solvents.
21. A solution or dispersion as claimed in claim 20 , wherein the three solvents have different boiling points.
22. A solution or dispersion as claimed in claim 20 , wherein a first solvent having a boiling point in the range from 100 to 150° C., a second solvent having a boiling point in the range from 130 to 180° C. and a third solvent having a boiling point in the range from 170 to below 200° C. are used, with these solvents being different.
23. A layer of an organic semiconductor, wherein the layer is produced by means of a process which comprises applying by means of a printing process the solution or dispersion as claimed in claim 1 .