Diketopyrrolopyrrole polymers for use in organic field effect transistors
The present invention relates to polymers comprising a repeating unit of the formula I, or III and their use as organic semiconductor in organic devices, especially an organic field effect transistor (OFET), or a device containing a diode and/or an organic field effect transistor. The polymers according to the invention have excellent solubility in organic solvents and excellent film-forming properties. In addition, high efficiency of energy conversion, excellent field-effect mobility, good on/off current ratios and/or excellent stability can be observed, when the polymers according to the invention are used in organic field effect transistors.
1. A copolymer of formula (VII)
wherein
A is a group of formula
COM 1 is a group of formula
a is 2,
n is number which results in a molecular weight of 10,000 to 1,000,000 Daltons,
Ar 1 and Ar 1′ are a group of formula
Ar 2 is a group of formula
and
R 1 and R 2 are the same or different and are selected from a branched C 8 -C 36 alkyl group.
2. The copolymer according to claim 1 , wherein R 1 and R 2 are a branched C 12 -C 24 alkyl group.
3. The copolymer according to claim 1 , which has a weight average molecular weight of 10,000 to 100,000 Daltons.
4. A semiconductor device comprising the copolymer according to claim 1 .
5. The semiconductor device according to claim 4 is an organic field effect transistor.
6. A process for preparing an organic semiconductor device, the process comprising:
applying a solution and/or dispersion comprising the copolymer according to claim 1 in an organic solvent to a substrate; and
removing the solvent.
7. An integrated circuit comprising the organic field effect transistor according to claim 6 .
8. A process for preparing the copolymer of claim 1 comprising:
reacting a dihalogenide X 10 -A-X 10 with an equimolar amount of a diboronic acid or diboronate corresponding to formula
or
reacting a dihalogenide of formula
with an equimolar amount of a diboronic acid or diboronate corresponding to formula X 11 -A-X 11 ,
wherein X 10 is halogen, and
X 11 is independently in each occurrence —B(OH) 2 , —B(OY 1 ) 2 ,
—BF 3 Na, —BF 3 N(Y 15 ) 4 , or BF 3 K, wherein Y 1 is independently in each occurrence a C 1 -C 10 alkyl group and Y 2 is independently in each occurrence a C 2 -C 10 alkylene group, Y 13 and Y 14 are independently of each other hydrogen, or a C 1 -C 10 alkyl group, Y 15 is H, or a C 1 -C 25 alkyl group, which may optionally be interrupted by —O—, in a solvent and in the presence of a catalyst; or
reacting a dihalogenide of formula X 10 -A-X 10 with an equimolar amount of an organo tin compound corresponding to formula
or
reacting a dihalogenide of formula
with an equimolar amount of an organo tin compound corresponding to formula X 11′ -A-X 11′ , wherein
X 11′ is independently in each occurrence —SnR 207 R 208 R 209 , wherein R 207 , R 208 and R 209 are identical or different and are H or C 1 -C 6 alkyl, or two of the groups R 207 , R 208 and R 209 form a ring and these groups are optionally branched.
9. The process according to claim 8 , wherein X 10 is Br.
10. The copolymer according to claim 1 , wherein R 1 and R 2 are the same or different and are selected from 2-hexyldecyl and decyl-tetradecyl.
11. The copolymer according to claim 3 , having a weight average molecular weight of 20,000 to 60,000 Daltons.