CONDUCTIVE POLYMER OF POLY(THIO- OR SELENO-)PHENE TYPE

Abstract

The present invention relates to a conductive polymer material of poly(thio- or seleno-)phene type containing at least two distinct species of counteranion, including a first species which is an anionic form of sulphuric acid, and a second species of counteranion selected from triflate, triflimidate, tosylate, mesylate, perchlorate and hexafluorophosphate. The invention also relates to a process for preparing such a material and the use thereof as conductive film. The invention also targets a substrate coated at least partly by a film of a material as defined above, a device comprising a material as defined above as conductive material, and also the use thereof in the organic electronics, organic thermoelectricity, organic photovoltaic and organic photodetector fields.

Claims

1. A conductive polymeric material of poly(thio or seleno)phene type comprising at least two distinct kinds of counteranion, including a first kind which is an anionic form of sulfuric acid and a second kind of counteranion chosen from triflate, triflimidate, tosylate, mesylate, perchlorate and hexafluorophosphate.

2. The material as claimed in claim 1, comprising at least hydrogensulfate and triflate counteranions.

3. The material as claimed in claim 1, based on a thiophene polymer deriving from the polymerization of monomer(s) chosen from thiophene, 3-alkylthiophenes, 3,4-dialkylthiophenes, 3,4-cycloalkylthiophenes, 3,4-dialkoxythiophenes and 3,4-alkylenedioxythiophenes, in which the alkyl groups, which are identical or different, are of formula C.sub.nH.sub.2n+1 with n between 1 and 12.

4. The material as claimed in claim 1, in which the monomers are chosen from thiophene, 3,4-ethylenedioxythiophene (EDOT), 3-hexylthiophene and 3,4-propylenedioxythiophene (PRODOT).

5. The material as claimed in claim 1, based on poly(3,4-ethylenedioxythiophene) (PEDOT).

6. The material as claimed in claim 1, based on a selenophene polymer deriving from the polymerization of monomer(s) chosen from selenophene, 3-alkylselenophenes, 3,4-dialkylselenophenes, 3,4-cycloalkylselenophenes, 3,4-dialkoxyselenophenes and 3,4-alkylenedioxyselenophenes, in which the alkyl groups, which are identical or different, are of formula C.sub.nH.sub.2n+1 with n between 1 and 12.

7. The material as claimed in claim 1, in which the monomers are chosen from selenophene, 3,4-ethylenedioxyselenophene (EDOS), 3-hexylselenophene and 3,4-propylenedioxyselenophene (PRODOS).

8. The material as claimed in claim 1, having a conductivity at least equal to 1000 S/cm, measured by the 4-point method, using a Loresta EP MCP-T360 conductivity meter.

9. A process for the preparation of a material as claimed in claim 1, comprising at least the stages consisting in: (a) having available a polymeric material of poly(thio or seleno)phene type comprising at least one anionic entity chosen from triflate, triflimidate, tosylate, mesylate, perchlorate and hexafluorophosphate, (b) bringing said material into contact with an aqueous solution of a sulfur-comprising acid under conditions favorable to the immobilization of an anionic form of said acid within the polymeric material, and (c) having available said material comprising a first anionic entity chosen from triflate, triflimidate, tosylate, perchlorate and hexafluorophosphate and a second entity corresponding to an anionic form of said sulfur-comprising acid.

10. The process as claimed in claim 9, in which said material of stage (a) is obtained beforehand by polymerization in a solvent medium of thio or selenophene monomer(s) in the presence of an oxidizing solution of iron(III) triflate, triflimidate, tosylate, mesylate, perchlorate or hexafluorophosphate and of an effective amount of block copolymer of polyethylene glycol-polypropylene glycol-polyethylene glycol (PEG-PPG-PEG) type and is purified by aqueous washing before it is employed in stage (b).

11. The process as claimed in claim 9, in which the temperature during the operation in which the material is brought into contact with the aqueous solution of sulfur-comprising acid in stage b) is between 120 C. and 200 C.

12. A process for increasing the conductivity of a polymeric material of poly(thio or seleno)phene type comprising at least one first kind of counteranion which is an anionic form of sulfuric acid and a second kind of counteranion chosen from triflate, triflimidate, tosylate, mesylate, perchlorate and hexafluorophosphate, which is provided in the form of a film, appearing at the surface of a solid substrate, comprising the stage consisting in bringing said film into contact with an aqueous solution of a sulfur-comprising acid under conditions favorable to the immobilization of an anionic form of said acid within the polymeric material.

13. A method for obtaining a conductive film using a material as claimed in claim 1.

14. A substrate coated at least in part with a film of a material as claimed in claim 1.

15. The substrate as claimed in claim 14, made of glass, of silicon, of woven material or of organic and/or polymeric nature.

16. A device comprising, as conductor material, a material as claimed in claim 1.

17. (canceled)

18. The material as claimed in claim 1, having a conductivity varying from approximately 1500 S/cm to approximately 2500 S/cm, measured by the 4-point method, using a Loresta EP MCP-T360 conductivity meter.

19. The process as claimed in claim 9, in which the temperature during the operation in which the material is brought into contact with the aqueous solution of sulfur-comprising acid in stage b) is between 140 C. and 180 C.

20. A method for obtaining a conductive film using a material obtained according to claim 9.

21. A substrate coated at least in part with a film of a material obtained according to claim 9.

22. A device comprising, as conductor material, a material obtained according to claim 9.

Description

EXAMPLES

Example 1: Synthesis of PEDOT with Different Acid Treatments

[0082] 2 ml of a 20% by weight solution of polyethylene glycol-polypropylene glycol-polyethylene glycol (PEG-PPG-PEG) (Mn=5800 g.Math.mol.sup.1) in ethanol are prepared with stirring in an ultrasonic bath for 4 hours.

[0083] 240 mg of Fe(OTf).sub.3 are added to the solution with stirring.

[0084] The solution is left stirring for an additional 30 minutes.

[0085] The solution is subsequently cooled to 5 C. and 20 l of EDOT are added.

[0086] The solution is immediately placed in an ultrasonic bath at 5 C. for 1 minute.

[0087] The solution is spin coated onto a sheet of Corning Eagle XG glass (1010 cm) and then annealed for 10 minutes on a heating plate at 70 C. in the open air.

[0088] The glass sheet is cut into 2.51.25 cm pieces and the conductivity of the films obtained is measured at 1200 S/cm (+/20 S/cm) by 4-point measurement for a mean thickness of 70 nm (+/5 nm).

[0089] These films are dipped in an acid bath at pH=1 for one hour and then dried on a heating plate at 160 C. for 30 minutes.

[0090] The conductivity of the films is measured by the Van der Pauw (4 point) method and compared with the value before acid treatment.

[0091] The values are collated in the table below.

TABLE-US-00001 Conductivity Conductivity after Sample (S/cm) Acid treatment treatment (S/cm) 1 1207 CF.sub.3SO.sub.3H (pH = 1) 1376 2 1192 HCl (pH = 1) 341 3 1230 HNO.sub.3 (pH = 1) 671 4 1215 CH.sub.3SO.sub.3H (pH = 1) 1690 for 1 h 5 1220 H.sub.2SO.sub.4 (pH = 1) 2541 for 1 h

[0092] It is noticed that samples 1, 4 and 5, which have been subjected to a treatment with a sulfur-comprising or sulfonic acid, exhibit very high conductivities after treatment, in contrast to samples 2 and 3, which were treated with HCl or HNO.sub.3.

Example 2: Synthesis of Highly Conductive PEDOT:HSO.SUB.4

[0093] 2 ml of a 20% by weight solution of PEG-PPG-PEG (Mn=5800 g.Math.mol.sup.1) in ethanol are prepared with stirring in an ultrasonic bath for 4 hours.

[0094] 240 mg of Fe(OTf).sub.3 are added to the solution with stirring.

[0095] The solution is left stirring for an additional 30 minutes.

[0096] The solution is subsequently cooled to 5 C. and 20 l of EDOT are added.

[0097] The solution is immediately placed in an ultrasonic bath at 5 C. for 1 minute.

[0098] The solution is spin coated onto a sheet of Corning Eagle XG glass (1010 cm) and then annealed for 10 minutes on a heating plate at 70 C. in the open air.

[0099] The glass sheet is cut into 2.51.25 cm pieces and the conductivity of the films obtained is measured at 1200 S/cm (+/20 S/cm) by 4-point measurement for a mean thickness of 70 nm (+/5 nm).

[0100] These films are dipped in a bath of sulfuric acid at pH=1 for a predetermined period of time (1 min, 10 min, 30 min, 1 h, 2 h, 5 h or 24 h) and then dried on a heating plate at 160 C. for 30 minutes.

[0101] The conductivity of the films is measured by the Van der Pauw (4 point) method and compared with the value before acid treatment.

[0102] The values are collated in the table below.

TABLE-US-00002 Conductivity Conductivity after Sample (S/cm) Acid treatment treatment (S/cm) 6 1262 H.sub.2SO.sub.4 (pH = 1) 1450 for 1 min 7 1189 H.sub.2SO.sub.4 (pH = 1) 1806 for 10 min 8 1189 H.sub.2SO.sub.4 (pH = 1) 2502 for 30 min 9 1301 H.sub.2SO.sub.4 (pH = 1) 2480 for 1 h 10 1338 H.sub.2SO.sub.4 (pH = 1) 2512 for 2 h 11 1186 H.sub.2SO.sub.4 (pH = 1) 2521 for 24 h

[0103] All of the samples treated with H.sub.2SO.sub.4 have very high conductivities after treatment. The conductivities after acid treatment are all the higher when the treatment time is greater than 30 minutes.

Example 3: Synthesis of Highly Conductive PEDOT:HSO.SUB.4

[0104] 2 ml of a 20% by weight solution of PEG-PPG-PEG (Mn=5800 g.Math.mol.sup.1) in ethanol are prepared with stirring in an ultrasonic bath for 4 hours.

[0105] 240 mg of Fe(OTf).sub.3 are added to the solution with stirring.

[0106] The solution is left stirring for an additional 30 minutes.

[0107] The solution is subsequently cooled to 5 C. and 20 l of EDOT are added.

[0108] The solution is immediately placed in an ultrasonic bath at 5 C. for 1 minute.

[0109] The solution is spin coated onto a sheet of Corning Eagle XG glass (1010 cm) and then annealed for 10 minutes on a heating plate at 70 C. in the open air.

[0110] The glass sheet is cut into 2.51.25 cm pieces and the conductivity of the films obtained is measured at 1200 S/cm (+/20 S/cm) by 4-point measurement for a mean thickness of 70 nm (+/5 nm).

[0111] These films are dipped in a bath of sulfuric acid at pH=1 for 30 minutes and then dried on a heating plate at different temperatures (140 C., 160 C. or 180 C.) for 30 minutes.

[0112] The conductivity of the films is measured by the Van der Pauw (4 point) method and compared with the value before acid treatment.

[0113] The values are collated in the table below.

TABLE-US-00003 Conductivity Conductivity after Sample (S/cm) Acid treatment treatment (S/cm) 12 1238 H.sub.2SO.sub.4 (pH = 1) at 1920 140 C. 13 1276 H.sub.2SO.sub.4 (pH = 1) at 2520 160 C. 14 1286 H.sub.2SO.sub.4 (pH = 1) at 1723 180 C. 15 1238 H.sub.2SO.sub.4 (pH = 1) at 1453 200 C.

[0114] All of the samples treated with H.sub.2SO.sub.4 have very high conductivities after treatment. The conductivities after acid treatment are all the higher when the treatment temperature is 160 C.

Example 4: Synthesis of Highly Conductive PRODOT:HSO.SUB.4

[0115] 2 ml of a 20% by weight solution of PEG-PPG-PEG (Mn=5800 g.Math.mol.sup.1) in ethanol are prepared with stirring in an ultrasonic bath for 4 hours.

[0116] 240 mg of Fe(OTf).sub.3 are added to the solution with stirring.

[0117] The solution is left stirring for an additional 30 minutes.

[0118] The solution is subsequently cooled to 5 C. and 25 l of 3,4-propylenedioxythiophene (PRODOT) are added.

[0119] The solution is immediately placed in an ultrasonic bath at 5 C. for 1 minute.

[0120] The solution is spin coated onto a sheet of Corning Eagle XG glass (2.52.5 cm) and then annealed for 10 minutes on a heating plate at 70 C. in the open air.

[0121] The film is dipped in a bath of sulfuric acid at pH=1 for 30 minutes and then dried on a heating plate at 160 C. for 30 minutes.

[0122] The conductivity of the film, measured by the Van der Pauw (4 point) method, is 1500 S.Math.cm.sup.1 and its thickness is 70 nm (+/5 nm).

Example 5: Synthesis of Highly Conductive PEDOS:HSO.SUB.4

[0123] 2 ml of a 20% by weight solution of PEG-PPG-PEG (Mn=5800 g.Math.mol.sup.1) in ethanol are prepared with stirring in an ultrasonic bath for 4 hours.

[0124] 240 mg of Fe(OTf).sub.3 are added to the solution with stirring.

[0125] The solution is left stirring for an additional 30 minutes.

[0126] The solution is subsequently cooled to 5 C. and 25 l of 3,4-ethylenedioxyselenophene (EDOS) are added.

[0127] The solution is immediately placed in an ultrasonic bath at 5 C. for 1 minute.

[0128] The solution is spin coated onto a sheet of Corning Eagle XG glass (2.52.5 cm) and then annealed for 10 minutes on a heating plate at 70 C. in the open air.

[0129] The film is dipped in a bath of sulfuric acid at pH=1 for 30 minutes and then dried on a heating plate at 160 C. for 30 minutes.

[0130] The conductivity of the film, measured by the Van der Pauw (4 point) method, is 1650 S.Math.cm.sup.1 and its thickness is 70 nm (+/5 nm).

Example 6: Synthesis of Highly Conductive PEDOT:HSO.SUB.4 .from PEDOT:OTs

[0131] 2 ml of a 20% by weight solution of PEG-PPG-PEG (Mn=5800 g.Math.mol.sup.1) in ethanol are prepared with stirring in an ultrasonic bath for 4 hours.

[0132] 240 mg of Fe(OTf).sub.3 are added to the solution with stirring.

[0133] The solution is left stirring for an additional 30 minutes.

[0134] The solution is subsequently cooled to 5 C. and 20 l of 3,4-ethylenedioxythiophene (EDOT) are added.

[0135] The solution is immediately placed in an ultrasonic bath at 5 C. for 1 minute.

[0136] The solution is spin coated onto a sheet of Corning Eagle XG glass (2.52.5 cm) and then annealed for 10 minutes on a heating plate at 70 C. in the open air.

[0137] The film is dipped in a bath of sulfuric acid at pH=1 for 30 minutes and then dried on a heating plate at 160 C. for 30 minutes.

[0138] The conductivity of the film, measured by the Van der Pauw (4 point) method, is 1750 S.Math.cm.sup.1 and its thickness is 70 nm (+/5 nm).