Metal oxide charge transport material doped with organic molecules

• US 9,431,621 B2
• Filed: 03/13/2012
• Issued: 08/30/2016
• Est. Priority Date: 03/13/2012
• Status: Active Grant

• Current Assignee: Board of Regents of the University of Michigan (University of Michigan)
• Original Assignee: Board of Regents of the University of Michigan (University of Michigan)
• Inventors: Forrest, Stephen R., Lassiter, Brian E.
• Primary Examiner(s): Ahmed, Selim
• Assistant Examiner(s): RAHMAN, MOIN M
• Application Number:
  US13/418,875
• Publication Number:
  US 20130240840A1
• Time in Patent Office: 1,631 Days
• Field of Search: 257/13, 257 79-103, 257/918, 257/40, 257642-643, 257/759, 438 22- 47, 438/69, 438/493, 438/503, 438/507, 438/956
• US Class Current: 1/1
• CPC Class Codes: H10K 30/30 comprising bulk heterojunctions, e.g. interpenetrating networks of donor and acceptor material domains
• CPC Class Codes: H10K 30/50 Photovoltaic [PV] devices
• CPC Class Codes: H10K 85/311 Phthalocyanine
• CPC Class Codes: H10K 85/6572 comprising only nitrogen in the heteroaromatic polycondensed ring system, e.g. phenanthroline or carbazole
• CPC Class Codes: Y02E 10/549 Organic PV cells

Abstract

Doping metal oxide charge transport material with an organic molecule lowers electrical resistance while maintaining transparency and thus is optimal for use as charge transport materials in various organic optoelectronic devices such as organic photovoltaic devices and organic light emitting devices.

Claims

1. A transparent metal oxide charge transport material for use in an optoelectronic device, the charge transport material comprising:

a metal oxide material doped with an organic dopant material, wherein the organic dopant material is selected from the group consisting of acridine orange base (AOB), and chloroboron subphthalocyanine (SubPc),

wherein the metal oxide material is doped with 1 to 20 vol. % of the organic dopant material, whereby electrical resistivity of the metal oxide material is reduced while maintaining transparency of the metal oxide charge transport material.

2. The metal oxide charge transport material of claim 1, wherein the metal oxide material is selected from the group consisting of MoO₃, CrO₃, V₂O₅, WO₃, NiO, Cr₃O₄, Cr₂O₃, CuO, RuO₂, TiO₂, Ta₂O₅, SnO₂, and Cu₂O.

3. The metal oxide charge transport material of claim 1, wherein the HOMO of the organic dopant is similar to or smaller than the LUMO of the metal oxide material.

4. The metal oxide charge transport material of claim 1, wherein the LUMO of the organic dopant is similar to or larger than the HOMO of the metal oxide material.

5. The metal oxide charge transport material of claim 1, wherein the metal oxide material is doped with 10 vol. % of the organic dopant material.

6. An organic photosensitive device comprising:

a first electrode;

a second electrode;

a photoactive region disposed between the first electrode and the second electrode; and

a transparent charge transport layer disposed between the photoactive region and at least one of the first and second electrodes, wherein the charge transport layer comprises a metal oxide material doped with an organic dopant material,

wherein the organic dopant material is selected from the group consisting of acridine orange base (AOB), and chloroboron subphthalocyanine (SubPc),

wherein the metal oxide material is doped with 1 to 20 vol. % of the organic dopant material, whereby electrical resistivity of the metal oxide material is reduced while maintaining transparency of the metal oxide charge transport material.

7. The device of claim 6, wherein the metal oxide material is selected from the group consisting of MoO₃, CrO₃, V₂O₅, WO₃, NiO, Cr₃O₄, Cr₂O₃, CuO, RuO₂, TiO₂, Ta₂O₅, SnO₂, and Cu₂O.

8. The device of claim 6, wherein the HOMO of the organic dopant is similar to or smaller than the LUMO of the metal oxide material.

9. The device of claim 6, wherein the LUMO of the organic dopant is similar to or larger than the HOMO of the metal oxide material.

10. The device of claim 6, wherein the metal oxide material is doped with 10 vol. % of the organic dopant material.

11. The device of claim 6, wherein the photoactive region comprises an organic donor material and an organic acceptor material forming a donor-acceptor heterojunction.

31. The device of claim 6, wherein the charge transport layer has a thickness of 150 nm or higher.

12. An organic photosensitive device comprising:

an anode;

multiple subcells in series, each subcell comprising;

an electron donor layer, and an electron acceptor layer in contact with the electron donor layer forming a donor-acceptor heterojunction, an electron-hole recombination zone separating the subcells; and

a cathode,

wherein the electron-hole recombination zone comprises a transparent metal oxide material doped with an organic dopant material, wherein the organic dopant material is selected from the group consisting of acridine orange base (AOB), and chloroboron subphthalocyanine (SubPc),

wherein the metal oxide material is doped with 1 to 20 vol. % of the organic dopant material, whereby electrical resistivity of the metal oxide material is reduced while maintaining transparency of the metal oxide material.

13. The device of claim 12, wherein the metal oxide material is selected from the group consisting of MoO₃, CrO₃, V₂O₅, WO₃, NiO, Cr₃O₄, Cr₂O₃, CuO, RuO₂, TiO₂, Ta₂O₅, SnO₂, and Cu₂O.

14. The device of claim 12, wherein the HOMO of the organic dopant is similar to or smaller than the LUMO of the metal oxide material.

15. The device of claim 12, wherein the LUMO of the organic dopant is similar to or larger than the HOMO of the metal oxide material.

16. The device of claim 12, wherein the metal oxide material is doped with 10 vol. % of the organic dopant material.

32. The device of claim 12, wherein the metal oxide material has a thickness of 150 nm or higher.

17. An organic light emitting device comprising:

an anode;

a cathode; and

at least one emissive layer and at least one transparent charge transport layer disposed between the anode and the cathode, wherein the at least one charge transport layer comprises a metal oxide material doped with an organic dopant material, wherein the organic dopant material is selected from the group consisting of acridine orange base (AOB), and chloroboron subphthalocyanine (SubPc),

wherein the metal oxide material is doped with 1 to 20 vol. % of the organic dopant material, whereby electrical resistivity of the charge transport layer is reduced while maintaining transparency of the charge transport layer.

18. The device of claim 17, wherein the metal oxide material is selected from the group consisting of MoO₃, CrO₃, V₂O₅, WO₃, NiO, Cr₃O₄, Cr₂O₃, CuO, RuO₂, TiO₂, Ta₂O₅, SnO₂, and Cu₂O.

19. The device of claim 17, wherein the HOMO of the organic dopant is similar to or smaller than the LUMO of the metal oxide material.

20. The device of claim 17, wherein the LUMO of the organic dopant is similar to or larger than the HOMO of the metal oxide material.

21. The device of claim 17, wherein the metal oxide material is doped with 10 vol. % of the organic dopant material.

22. The device of claim 17, wherein the at least one charge transport layer is an electron transport layer in direct contact with the at least one emissive layer and disposed between the at least one emissive layer and the cathode.

23. The device of claim 17, wherein the at least one charge transport layer is a hole transport layer in direct contact with the at least one emissive layer and disposed between the at least one emissive layer and the anode.

24. A stacked organic light emitting device comprising:

an anode;

a cathode;

a plurality of emissive regions disposed between the anode and the cathode; and

a transparent charge generation layer disposed between successive emissive regions, wherein the charge generation layer comprises a metal oxide material doped with an organic dopant material, wherein the organic dopant material is selected from the group consisting of, acridine orange base (AOB), and chloroboron subphthalocyanine (SubPc),

wherein the metal oxide material is doped with 1 to 20 vol. % of the organic dopant material, whereby electrical resistivity of the charge generation layer is reduced while maintaining transparency of the charge generation layer.

25. The device of claim 24, wherein the metal oxide material is selected from the group consisting of MoO₃, CrO₃, V₂O₅, WO₃, NiO, Cr₃O₄, Cr₂O₃, CuO, RuO₂, TiO₂, Ta₂O₅, SnO₂, and Cu₂O.

26. The device of claim 24, wherein the HOMO of the organic dopant is similar to or smaller than the LUMO of the metal oxide material.

27. The device of claim 24, wherein the LUMO of the organic dopant is similar to or larger than the HOMO of the metal oxide material.

28. The device of claim 24, wherein the metal oxide material is doped with 10 vol. % of the organic dopant material.

29. The device of claim 24, wherein the at least one charge transport layer is an electron transport layer in direct contact with the at least one emissive layer and disposed between the at least one emissive layer and the cathode.

30. The device of claim 24, wherein the at least one charge transport layer is a hole transport layer in direct contact with the at least one emissive layer and disposed between the at least one emissive layer and the anode.

33. The device of claim 24, wherein the at least one charge transport layer has a thickness of 150 nm or higher.

34. The device of claim 24, wherein the charge generation layer has a thickness of 150 nm or higher.