Metathesis polymers as dielectrics

Abstract

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.

Claims

1. An electronic device containing at least one dielectric material which comprises an oxacycloolefinic polymer, which comprises a polymer chain of the formula III ##STR00037## wherein n ranges from 3 to 100 000, each of R.sub.2 to R.sub.5 is selected from hydrogen and C.sub.1-C.sub.4alkyl, and R is hydrogen, C.sub.1-C.sub.25alkyl, C.sub.1-C.sub.25haloalkyl, phenyl, phenyl-C.sub.1-C.sub.4alkyl, cyclopentyl, or cyclohexyl, wherein phenyl moiety or cyclopentyl or cyclohexyl moiety itself is unsubstituted or substituted by C.sub.1-C.sub.4alkyl, C.sub.1-C.sub.4alkoxy, 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 ##STR00038## wherein n ranges from 3 to 100 000, each of R.sub.2 to R.sub.5 is selected from hydrogen and C.sub.1-C.sub.4alkyl, and R is hydrogen, C.sub.1-C.sub.25alkyl, C.sub.1-C.sub.25haloalkyl, phenyl, phenyl-C.sub.1-C.sub.4alkyl, cyclopentyl, or cyclohexyl, wherein phenyl moiety or cyclopentyl or cyclohexyl moiety itself is unsubstituted or substituted by C.sub.1-C.sub.4alkyl, C.sub.1-C.sub.4alkoxy, OH, halogen.

Description

EXAMPLE 1

(1) a) Preparation of Monomer 1

(2) ##STR00029##

(3) 100 g of p-isopropylaniline (1 eq, 0.74 mol) is added to a solution of 122.9 g of exo-3,6-Epoxy-1,2,3,6-tetrahydrophthalic anhydride (1 eq, 0.74 mol) in acetone and stirred for 2 h. The resulting precipitate is filtrated, washed with acetone, dried and mixed with 27 g of sodium acetate in 550 mL of acetic anhydride. The mixture is then stirred for 2 h at reflux and cooled down at 0° C. The resulting precipitate is filtrated, washed with water, recrystalized in methanol and dried to yield the corresponding 1 as a pure white solid. Yield=71%; .sup.1H-NMR (CDCl.sub.3): δ (ppm) 1.18 (d, 6H), 1.56 (s, 2H), 2.79 (s, 2H), 2.94 m, 1H), 3.03 (s, 2H), 5.42 (s, 2H), 6.59 (s, 2H), 7.20 (d, 2H), 7.33 (d, 2H).

(4) b) Polymer P1

(5) ##STR00030##

(6) 63 mg of (1,3-Bis-(2,4,6-trimethylphenyl)-2-imidazolidinylidene)dichloro(oisopropoxyphenylmethylene)ruthenium (0.5% mol, 100 μmol) is added to 2 g of 1 (1 eq, 18 mmol) in 15 mL of anhydrous dichloromethane under Nitrogen. After being stirred for 4 h at reflux, 10 mL of anhydrous dichloromethane and 1 mL of ethylvinylether are added. The mixture is poured in cold ethanol. The precipitate is filtrated, dissolved in a minimum amount of dichloromethane and poured in cold heptane. The precipitate is filtrated, dried to yield the corresponding pure polymer P1 as a white solid. Yield=61% Mw=161 kDa/PDI=2.1/Tg=228° C. Sodium content 14 mg/kg Phosphore content 24 mg/kg Ruthenium content 117 mg/kg

EXAMPLE 2

In Analogy to Example 1, The Following Polymers are Prepared

(7) ##STR00031##
a) Polymer P2: Mw=46.5 kDa PDI=1.46 Tg=238° C.

(8) ##STR00032##
b) Polymer P3: Mw=69 kDa PDI=1.60 Tg=144° C.

EXAMPLE 3

Preparation of a Top-gate, Bottom Contact (TGBC) Field Effect Transistor Comprising a Gate Dielectric Layer of P1

(9) Gold is sputtered onto poly(ethylene terephthalate) (PET) foil to form an approximately 40 nm thick film and then source/drain electrodes (channel length: 10 μm; channel width: 10 mm) are structured by photolithography process. A 0.75% (weight/weight) solution of a diketopyrrolopyrrole (DPP)-thiophene-polymer (polymer 21-1 according to example 1 of WO2010/049321:

(10) ##STR00033##
in toluene is filtered through a 0.45 μm polytetrafluoroethylene (PTFE) filter and then applied by spin coating (15 seconds at 1300 rpm, acceleration 10.000 rpm/s. The wet organic semi-conducting polymer layer is dried at 100° C. on a hot plate for 30 seconds. A 8% (weight/weight) solution of P1 in Methoxypropyl Acetate is filtered through a 0.45 μm filter and then applied by spin coating (1100 rpm, 60 seconds). The wet layer film is pre-baked at 100° C. for 20 minutes on a hot plate to obtain a 365 nm thick layer. Gate electrodes of gold (thickness approximately 120 nm) are evaporated through a shadow mask on the P1 layer. The whole process is performed without a protective atmosphere.

(11) Measurement of the characteristics of the top gate, bottom contact (TGBC) field effect transistors are measured with a Keithley® 2612A semiconductor parameter analyser.

(12) The drain current I.sub.ds in relation to the gate voltage V.sub.gs (transfer curve) for the top-gate, bottom-contact (TGBC) field effect transistor comprising a P1 gate dielectric at a source voltage V.sub.sd of −20V (upper curves) is shown in FIG. 1.

(13) The top-gate, bottom-contact (TGBC) field effect transistor comprising a P1 as gate dielectric shows a mobility of 0.36 cm.sup.2/Vs (calculated for the saturation regime) and an Ion/Ioff ration of 5 E+5.

(14) The drain current I.sub.ds in relation to the drain voltage V.sub.ds (output curve) for the top-gate, bottom-contact (TGBC) field effect transistor comprising P1 at a gate voltage V.sub.gs of 0V (squares), −5V (stars), −10V (lozenges), −15V (triangles), and −20V (circles) is shown in FIG. 2.

EXAMPLE 4

Preparation of a Capacitor

(15) A 8% (weight/weight) solution of polymer P1 as obtained in example 1b in Methoxypropyl Acetate is filtered through a 0.45 μm filter and applied on a clean glass substrate with indium tin oxide (ITO) electrodes by spin coating (1100 rpm, 30 seconds). The wet film is pre-baked at 100° C. for 20 minutes on a hot plate to obtain a 490 nm thick layer. Gold electrodes (area=3 mm.sup.2) are then vacuum-deposited through a shadow mask on the P1 layer at <1×10.sup.−6 Torr.

(16) The capacitor thus obtained is characterized in the following way:

(17) The relative permittivity ∈.sub.r and the loss factor tg(δ)=∈.sub.r″ are deduced from the complex capacity measured with a LCR meter Agilent 4284A (signal amplitude 1 V). Current /Voltage (I/V) curves are obtained with a semiconductor parameter analyser Agilent 4155C. The breakdown voltage is the voltage Ed where the current reaches a value of 1 μA. The volume resistivity ρis calculated from the resistance, sample thickness and electrode surface.

(18) In the same way, capacitors are prepared and investigated using polymers 2 and 3. results are compiled in the below table.

(19) TABLE-US-00001 ρ ε.sub.r ε.sub.r ε.sub.r″ ε.sub.r″ Ed Polymer [Ωcm] 20 Hz 100 kHz 20 Hz 100 kHz [V/μm] 1 2.5E+15 3.15 3.01 0.037 0.040 >190 2 1.9E+15 3.05 2.92 0.037 0.022 >143 3 3.8E+15 2.87 2.76 0.029 0.025 171

EXAMPLE 5

Alternative Preparation of Polymer

(20) a) Preparation of Monomer 2

(21) ##STR00034##

(22) 100 g of p-isopropylaniline (1 eq, 0.74 mol) is added to a solution of 122.9 g of exo-3,6-Epoxy-1,2,3,6-tetrahydrophthalic anhydride (1 eq, 0.74 mol) in acetone. The mixture is then stirred for 2 h. The resulting precipitate is filtrated, washed with acetone and dried to yield the corresponding pure 2 as a white solid. Yield=87%

(23) .sup.1H-NMR (DMSO): δ (ppm) 1.19 (d, 6H), 2.67 (d, 1H), 2.79 (d, 1H), 2.83 (m, 1H), 5.03 (s, 1H), 5.14 (s, 1H), 6.50 (m, 2H), 7.15 (d, 2H), 7.44 (d, 2H), 9.60 (s, 1H).

(24) b) Preparation of Monomer 3

(25) ##STR00035##

(26) 182.4 g of 2 (1 eq, 0.63 mol) is added to 550 mL of acetic anhydride and 27 g of sodium acetate (0.5 eq, 0.33 mol). The mixture is then stirred for 2 h at reflux and cooled down at 0° C. The resulting precipitate is filtrated, washed with water, recrystalized for methanol and dried to yield the corresponding pure 3 as a white solid. Yield=79% .sup.1H-NMR (CDCl.sub.3): δ (ppm) 1.18 (d, 6H), 1.56 (s, 2H), 2.79 (s, 2H), 2.94 (m, 1H), 3.03 (s, 2H), 5.42 (s, 2H), 6.59 (s, 2H), 7.20 (d, 2H), 7.33 (d, 2H).

(27) c) Polymer P1′

(28) ##STR00036##

(29) 80 mg of Bis(tricyclohexylphosphine)benzylidine ruthenium(IV) dichloride (0.5% mol, 100 μmol) is added to 5 g of 3 (1 eq, 18 mmol) in 15 mL of anhydrous dichloromethane under Nitrogen. After being stirred for 5 h at room temperature, 10 mL of anhydrous dichloromethane and 1 mL of ethylvinylether are added. The mixture is poured in cold ethanol. The precipitate is filtrated, dissolved in a minimum amount of dichloromethane and poured in cold heptane. The precipitate is filtrated, dried to yield the corresponding pure polymer 1′ as a white solid. Yield=61%

(30) TABLE-US-00002 Mw = 128 kDa PDI = 3.4 Tg = 228° C. Na content 14 mg/kg P content 24 mg/kg Ru content 117 mg/kg

BRIEF DESCRIPTION OF FIGURES

(31) FIG. 1 shows drain current I.sub.ds in relation to the gate voltage V.sub.gs (transfer curve) for the TGBC field effect transistor comprising a polymer 1 gate dielectric at a source voltage V.sub.sd of −20V (upper curves).

(32) FIG. 2 shows the output curves for the TGBC field effect transistor comprising polymer 1 at a gate voltage V.sub.gs of 0V (squares), −5V (stars), −10V (lozenges), −15V (triangles), and −20V (circles).