Adhesion layer for solution-processed transition metal oxides on inert metal contacts

Patent metadata

Field	Value
Publication number	US-9390921-B2
Application number	US-201113992237-A
Country	US
Kind code	B2
Filing date	Dec 1, 2011
Priority date	Dec 6, 2010
Publication date	Jul 12, 2016
Grant date	Jul 12, 2016

Abstract

An ammonium thio-transition metal complex is used as an adhesion promoter for immobilizing temperature-stable transition metal oxide layers on an inert metal surface. The ammonium thio-transition metal complex comprises a transition metal selected from molybdenum, tungsten and vanadium, and is preferably ammonium tetrathiomolybdate. A precursor of the transition metal oxide is deposited on the inert metal surface by a solution-based process. The precursor is a dispersion or a dissolution of the transition metal oxide, a transition metal oxide hydrate, an ammonium salt of an acidic transition metal oxide hydrate or phosphoric acid-transition metal oxide complex in water or a phosphoric acid-transition metal oxide complex dissolved in a polar organic solvent.

First claim

The invention claimed is:

1. A process for preparing an organic thin-film transistor comprising source and drain electrodes, a gate electrode and an organic semiconductor layer, the process comprising:
pre-treating an inert metal surface of the source and drain electrodes with an ammonium thio-transition metal complex to form a pre-treated surface comprising an adhesion promoter layer comprising the ammonium thio-transition metal complex; and
forming, on the pre-treated surface, a layer of a temperature-stable transition metal oxide, thereby immobilizing the temperature-stable transition metal oxide on the adhesion promoter layer,
wherein the adhesion promoter layer is in contact with the inert metal surface and the temperature-stable transition metal oxide layer is in contact with the adhesion promoter layer.

2. The process according to claim 1 wherein the ammonium thio-transition metal complex comprises a transition metal selected from molybdenum, tungsten and vanadium.

3. The process according to claim 1 wherein the ammonium thio-transition metal complex is a tetrathio-transition metal complex.

4. The process according to claim 3 wherein the ammonium tetrathio-transition metal complex is ammonium tetrathiomolybdate.

5. The process according to claim 1 wherein the temperature-stable transition metal oxide is MoO 3 , WO 3 or V 2 O 5 .

6. The process according to claim 1 wherein a precursor of the temperature-stable transition metal oxide is deposited on the inert metal surface by a solution-based process.

7. The process according to claim 6 wherein the precursor is a dispersion or a dissolution of the temperature-stable transition metal oxide, a transition metal oxide hydrate, an ammonium salt of an acidic transition metal oxide hydrate or phosphoric acid-transition metal oxide complex in water or a phosphoric acid-transition metal oxide complex dissolved in a polar organic solvent.

8. The process according to claim 7 wherein the temperature-stable transition metal oxide is MoO 3 and the precursor is a dispersion or a dissolution of molybdenum trioxide, molybdic acid, ammonium molybdate or phosphomolybdic acid in water, or phosphomolybdic acid dissolved in a polar organic solvent.

9. The process according to claim 7 wherein the temperature-stable transition metal oxide is WO 3 and the precursor is a dispersion or a dissolution of tungsten trioxide, tungstic acid, ammonium tungstate or phosphotungstic acid in water, or phosphotungstic acid dissolved in a polar organic solvent.

10. The process according to claim 7 wherein the temperature-stable transition metal oxide is V 2 O 5 and the precursor is a dispersion or a dissolution of vanadium (V) oxide, ammonium metavanadate, vanadium(V) oxytriethoxide vanadium(V) oxytriethoxide, vanadium(V) oxytriisopropoxide or vanadium(V) oxytripropoxide dissolved in a polar organic solvent.

11. The process according to claim 6 wherein the solution-based process is selected from the group consisting of spin-coating, dip-coating and inkjet-printing.

12. The process according to claim 1 wherein the inert metal is silver, gold, or copper.

13. The process according to claim 12 wherein the inert metal is gold.

14. The process according to claim 1 wherein the temperature-stable transition metal oxide layer immobilized on the inert metal surface is stable up to temperatures of at least 140° C.

15. A process for preparing an organic thin-film transistor comprising source and drain electrodes, a gate electrode and an organic semiconductor layer, the process comprising:
(a) pre-treating an inert metal surface of the source and drain electrodes with an ammonium thio-transition metal complex to form an adhesion promoter layer comprising the ammonium thio-transition metal complex;
(b) depositing a solution comprising a temperature-stable transition metal oxide precursor onto the adhesion promoter layer; and
(c) annealing the deposited solution to form a layer of temperature-stable transition metal oxide, wherein the adhesion promoter layer is in contact with the inert metal surface and the temperature-stable transition metal oxide layer is in contact with the adhesion promoter layer.

16. A process according to claim 15 wherein step (a) comprises:
(i) cleaning the inert metal surface to remove organic contaminants;
(ii) depositing the ammonium thio-transition metal complex onto the inert metal surface; and
(iii) annealing of the treated surface in air.

17. A process according to claim 16 further comprising cleaning the metal surface by a UV-ozone treatment or an oxygen plasma treatment.

18. A process according to claim 15 wherein the step of depositing the solution comprising the temperature-stable transition metal oxide precursor is conducted by spin-coating, dip-coating or inkjet printing.

19. An organic thin-film transistor comprising source and drain electrodes, a gate electrode and an organic semiconductor layer, wherein the source and drain electrodes comprise an inert metal surface on which a temperature-stable transition metal oxide layer is immobilized by an adhesion promoter layer comprising an ammonium thio-transition metal complex, wherein the adhesion promoter layer is in contact with the inert metal surface and the temperature-stable transition metal oxide layer is in contact with the adhesion promoter layer.

20. An organic thin-film transistor according to claim 19 wherein the temperature-stable transition metal oxide is immobilized by:
(a) pre-treating the inert metal surface of the source and drain electrodes with the ammonium thio-transition metal complex to form the adhesion promoter layer comprising the ammonium thio-transition metal complex;
(b) depositing a solution comprising the temperature-stable transition metal oxide precursor onto the adhesion promoter layer; and
(c) annealing the deposited solution to form a layer of temperature-stable transition metal oxide.

21. An organic thin-film transistor according to claim 19 wherein the ammonium thio-transition metal complex comprises a transition metal selected from molybdenum, tungsten and vanadium.

22. An organic thin-film transistor according to claim 19 wherein the temperature-stable transition metal oxide is MoO 3 , WO 3 or V 2 O 5 .

23. An organic thin-film transistor according to claim 19 wherein the ammonium thio-transition metal complex is a tetrathio-transition metal complex.

24. An organic thin-film transistor according to claim 19 wherein the ammonium tetrathio-transition metal complex is ammonium tetrathiomolybdate.

Assignees

• Kugler Thomas
• Cambridge Display Tech Ltd

Inventors

• Kugler Thomas

Classifications

• H10P14/36 Primary

  characterised by treatments done before the formation of the materials · CPC title

• C23C18/1216

  Metal oxides (C23C18/1212 takes precedence) · CPC title

• C23C18/04 Primary

  Pretreatment of the material to be coated (C23C18/06 takes precedence) · CPC title

• C23C18/1241

  Metallic substrates · CPC title

• H01L21/02658 Primary

  Electricity · mapped topic