Electrically conducting organic polymer/nanoparticle composites and methods for use thereof

• US 20040206942A1
• Filed: 03/19/2004
• Published: 10/21/2004
• Est. Priority Date: 09/24/2002
• Status: Active Grant

• Current Assignee: LG Chem Limited (LG Corporation)
• Original Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Inventors: Hsu, Che-Hsiung
• Granted Patent: US 7,317,047 B2
• Time in Patent Office: Days
• US Class Current: 252/500
• CPC Class Codes: B82Y 10/00 Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: C08K 2201/011 Nanostructured additives
• CPC Class Codes: C08K 3/01 characterized by their specific function
• CPC Class Codes: H01B 1/12 organic substances organic macromolecular compounds or compositions C08
• CPC Class Codes: H01B 1/122 Ionic conductors
• CPC Class Codes: H01B 1/127 comprising five-membered aromatic rings in the main chain, e.g. polypyrroles, polythiophenes
• CPC Class Codes: H01B 1/128 comprising six-membered aromatic rings in the main chain, e.g. polyanilines, polyphenylenes
• CPC Class Codes: H01G 11/48 Conductive polymers
• CPC Class Codes: H01G 11/56 Solid electrolytes, e.g. gels; Additives therein
• CPC Class Codes: H01G 9/04 Electrodes or formation of dielectric layers thereon
• CPC Class Codes: H10K 10/464 Lateral top-gate IGFETs comprising only a single gate
• CPC Class Codes: H10K 2102/331 Nanoparticles used in non-emissive layers, e.g. in packaging layer
• CPC Class Codes: H10K 50/17 Carrier injection layers
• CPC Class Codes: H10K 71/60 Forming conductive regions or layers, e.g. electrodes
• CPC Class Codes: H10K 85/111 comprising aromatic, heteroaromatic, or aryl chains, e.g. polyaniline, polyphenylene or polyphenylene vinylene
• CPC Class Codes: H10K 85/1135 Polyethylene dioxythiophene [PEDOT]; Derivatives thereof
• CPC Class Codes: H10K 85/221 Carbon nanotubes
• CPC Class Codes: H10K 85/615 Polycyclic condensed aromatic hydrocarbons, e.g. anthracene
• CPC Class Codes: Y02E 10/549 : Organic PV cells
• CPC Class Codes: Y02E 60/13 : Energy storage using capacitors

Abstract

Compositions are provided comprising aqueous dispersions of electrically conducting organic polymers and a plurality of nanoparticles wherein pH can be adjusted for improved organic electronic device performance. Films deposited from invention compositions are useful as buffer layers in electroluminescent devices, such as organic light emitting diodes (OLEDs) and electrodes for thin film field effect transistors. Buffer layers containing nanoparticles may have a much lower conductivity than buffer layers without nanoparticles. In addition, when incorporated into an electroluminescent (EL) device, buffer layers according to the invention contribute to higher stress life of the EL device.

Claims

1. A composition comprising an aqueous dispersion of an electrically conductive organic polymer doped with a polymeric acid and a plurality of nanoparticles.

2. A composition according to claim 1, wherein said electrically conductive organic polymer is selected from polyanilines, polythiophenes polypyrroles, and combinations thereof.

3. A composition according to claim 1, wherein the pH is adjusted to between 1 and 8.

4. A composition according to claim 1, wherein said nanoparticles are inorganic nanoparticles.

5. A composition according to claim 4, wherein said inorganic nanoparticles are selected from silica, alumina, semiconductive inorganic oxide particles, insulating inorganic oxide particles, piezoelectric oxide nano-particles, pyroelectric oxide nano-particles, ferroelectric oxide nano-particles, photoconductive oxide nanoparticles, electrically conductive metal oxides, electrically conductive metal nanowires, and electrically conductive metal nanoparticles.

6. A composition according to claim 1, wherein said nanoparticles are organic nanoparticles.

7. A composition according to claim 6, wherein said organic nanoparticles are selected from colloid-forming polymeric acids, carbon nanotubes, carbon nano-particles, graphitized carbon nano-particles, graphitized carbon nano-fibers, piezoelectric polymers, pyroelectric polymers, ferroelectric polymers, and photoconductive polymers.

8. A composition according to claim 7, wherein said colloid-forming polymeric acid is a perfluoroethylene sulfonic acid.

9. A composition according to claim 1, wherein said nanoparticles have a particle size less than about 500 nm.

10. A composition according to claim 1, wherein said nanoparticles have a particle size less than about 250 nm.

11. A composition according to claim 1, wherein said nanoparticles have a particle size less than about 50 nm.

12. A composition according to claim 5, wherein the weight ratio of silica:

electrically conductive polymer is about 4;

1.

13. A composition according to claim 5, wherein the nanoparticle is an electrically semiconductive oxide, and a weight ratio of electrically semiconductive oxide to electrically conductive polymer is about 1.5 to 1.

14. A buffer layer comprising an electrically conductive polymer and a plurality of nanoparticles.

15. A buffer layer according to claim 14, wherein said electrically conductive polymer is selected from polyanilines, polythiophenes, polypyrroles, and combinations thereof.

16. A buffer layer according to claim 15, wherein said electrically conductive polymer is selected from PAni/PAAMPSA, PAni/PSSA, PEDT/PSSA, PEDT/PAAMPSA, PPy/PSSA, and PPy/PAAMPSA.

17. A buffer layer according to claim 14, wherein said nanoparticles are inorganic nanoparticles.

18. A buffer layer according to claim 14, wherein said inorganic nanoparticles are selected from silica, alumina, and electrically semiconductive metal oxides.

19. A buffer layer according to claim 14, wherein said nanoparticles are organic nanoparticles.

20. A buffer layer according to claim 14, wherein said organic nanoparticles are selected from colloid-forming polymeric sulfonic acids, colloid-forming polymeric acrylatic acids, colloid-forming polymeric phosphonics acids, and colloid-forming polymeric phosphoric acids.

21. A buffer layer according to claim 14 wherein said organic nano-particles comprise perfluoroethylenesulfonic acid.

23. A buffer layer according to claim 14, wherein said layer has a conductivity of less than about 1×

10<sup>−

3</sup> S/cm.

24. A buffer layer according to claim 14, wherein said layer has a conductivity of less than about 1×

10<sup>−

5</sup> S/cm.

22. A buffer layer made from an aqueous dispersion comprising poly(3,4-thylenedioxythiophene) and polymeric perfluroethylenesulfonic acid, wherein the aqueous dispersion has a pH greater than 2 and an equivalent ratio of polymeric perfluroethylenesulfonic acid to poly(3,4-thylenedioxythiophene) greater than 0.1.

25. An organic electronic device comprising a buffer layer comprising an electrically conductive polymer and a plurality of nanoparticles.

26. A device according to claim 25, wherein said electrically conductive polymer is selected from polyanilines, polythiophenes, polypyrroles, and combinations thereof.

27. A device according to claim 26, wherein said electrically conductive polymer is selected from PAni/PAAMPSA, PAni/PSSA, PEDT/PAAMPSA, PEDT/PSS, PPy/PSSA, and PPy/PAAMPSA.

28. A device according to claim 25, wherein said nanoparticles are inorganic nanoparticles.

29. A device according to claim 25, wherein said inorganic nanoparticles are selected from silica, alumina, or electrically semiconductive metal oxides.

30. Adevice according to claim 25, wherein said nanoparticles are organic nanoparticles.

31. A device according to claim 25, wherein said organic nanoparticles are selected from colloid-forming polymeric acids.

32. A device according to claim 25, wherein said buffer layer has a conductivity less than about 1×

10<sup>−

3</sup> S/cm.

43. An electronic device according to claim 25, wherein the device is selected from photoconductive cells, photoresistors, photoswitches, phototransistors, phototubes, IR detectors, photovoltaic device, solar cells coating materials for memory storage devices, field effect resistance devices, anti-static films, biosensors, electrochromic devices, solid electrolyte capacitors, energy storage devices, and electromagnetic shielding.

33. A thin film field effect transistor electrode, comprising an electrically conductive polymer and a plurality of nanoparticles.

34. A thin film field effect transistor electrode according to claim 33, wherein said electrically conductive polymer is selected from polyanilines, polythiophenes, polypyrroles, and combinations thereof.

35. A thin film field effect transistor electrode according to claim 33, wherein said nanoparticles are inorganic nanoparticles.

36. A thin film field effect transistor electrode according to claim 33, wherein said inorganic particles are metallic nanoparticles.

37. A thin film field effect transistor electrode according to claim 33, wherein said metallic nanoparticles are molybdenum nanoparticles.

38. A thin film field effect transistor electrode according to claim 33, wherein said nanoparticles are organic nanoparticles.

39. A thin film field effect transistor electrode according to claim 33, wherein said organic nanoparticles are selected from carbon nanotubes, graphitized carbon particles, and graphitized carbon nanofibers.

40. A thin film field effect transistor comprising an electrode according to claim 33.

41. A thin film field effect transistor according to claim 40, wherein said thin film field effect transistor has a conductivity greater than about 10 S/cm.

42. A method for reducing conductivity of an electrically conductive organic polymer film deposited from an aqueous dispersion onto a substrate to a value less than about 1×

10<sup>−

3</sup> S/cm, comprising adding a plurality of nanoparticles to said aqueous solution.