Metathesis polymers as dielectrics
Oxacycloolefinic polymers as typically obtained by metathesis polymerization using Ru-catalysts, show good solubility and are well suitable as dielectric material in electronic devices such as capacitors and organic field effect transistors.
1. An electronic device containing at least one dielectric material which comprises an oxacycloolefinic polymer, which comprises a polymer chain of the formula III
wherein n ranges from 3 to 100 000,
each of R 2 to R 5 is selected from hydrogen and C 1 -C 4 alkyl, and
R is hydrogen, C 1 -C 25 alkyl, C 1 -C 25 haloalkyl, phenyl, phenyl-C 1 -C 4 alkyl, cyclopentyl, or cyclohexyl, wherein phenyl moiety or cyclopentyl or cyclohexyl moiety itself is unsubstituted or substituted by C 1 -C 4 alkyl, C 1 -C 4 alkoxy, OH, halogen.
2. The electronic device according to claim 1 , wherein the oxacycloolefinic polymer is prepared by Ru-carbene catalyzed ring-opening metathesis polymerization of a bicyclic oxaolefin.
3. The electronic device according to claim 1 , wherein the oxacycloolefinic polymer is present as a layer essentially consisting of the oxacycloolefinic polymer.
4. The electronic device according to claim 1 , wherein the oxacycloolefinic polymer has a glass transition temperature, as determined by differential scanning calorimetry, above 90° C.
5. The electronic device according to claim 1 , wherein the electronic device is selected from capacitors, transistors such as organic field effect transistors, and devices comprising said capacitor and/or transistor.
6. The electronic device according to claim 1 , further comprising a substrate and comprising at least one further layer of a functional material in direct contact with the oxacycloolefinic polymer dielectric.
7. The electronic device according to claim 6 , wherein a layer of the oxacycloolefinic polymer as a dielectric material is in direct contact with an electrode layer and/or a semiconductor layer.
8. The electronic device according to claim 6 , wherein a layer of the oxacycloolefinic polymer as a dielectric material is in direct contact with a semiconductor layer that comprises a copolymer of the diketopyrrolopyrrole class.
9. The electronic device according to claim 1 , wherein the dielectric material is a dielectric layer in a printed electronic device.
10. The electronic device according to claim 9 , wherein the printed electronic device is a capacitor or an organic field-effect transistor.
11. A process for the preparation of an electronic device according to claim 1 , the process comprising;
providing a solution or dispersion of the oxacycloolefinic polymer of formula III in a solvent, and
applying the solution or the dispersion in the form of a layer onto a substrate, an electrode material or a semiconductor, and
drying said layer.
12. The process according to claim 11 , wherein the solution or the dispersion includes at least 8% by weight of the oxacycloolefinic polymer in solution.
13. The electronic device according to claim 1 , wherein the oxacycloolefinic polymer has a molecular weight, as determined by gel permeation chromatography, in a range of 10,000 to 1,000,000 g/mol.
14. A gate insulator layer comprising an oxacycloolefinic polymer comprising a polymer chain of formula III
wherein n ranges from 3 to 100 000,
each of R 2 to R 5 is selected from hydrogen and C 1 -C 4 alkyl, and
R is hydrogen, C 1 -C 25 alkyl, C 1 -C 25 haloalkyl, phenyl, phenyl-C 1 -C 4 alkyl, cyclopentyl, or cyclohexyl, wherein phenyl moiety or cyclopentyl or cyclohexyl moiety itself is unsubstituted or substituted by C 1 -C 4 alkyl, C 1 -C 4 alkoxy, OH, halogen.