HETEROPYRENE-BASED SEMICONDUCTOR MATERIALS FOR ELECTRONIC DEVICES AND METHODS OF MAKING THE SAME

• US 20090001353A1
• Filed: 06/26/2007
• Published: 01/01/2009
• Est. Priority Date: 06/26/2007
• Status: Active Grant

• Current Assignee: Eastman Kodak Company
• Original Assignee: Eastman Kodak Company
• Inventors: Robello, Douglas R., Shukla, Deepak, Ahearn, Wendy G., Carroll-Lee, Ann L., Welter, Thomas R.
• Granted Patent: US 7,781,076 B2
• Time in Patent Office: Days
• US Class Current: 257/40
• CPC Class Codes: H10K 10/464 Lateral top-gate IGFETs comprising only a single gate
• CPC Class Codes: H10K 10/466 Lateral bottom-gate IGFETs comprising only a single gate
• CPC Class Codes: H10K 85/6574 comprising only oxygen in the heteroaromatic polycondensed ring system, e.g. cumarine dyes
• CPC Class Codes: H10K 85/6576 comprising only sulfur in the heteroaromatic polycondensed ring system, e.g. benzothiophene
• CPC Class Codes: Y02E 10/549 Organic PV cells

Abstract

A thin layer of organic semiconductor material comprising a comprising an organic semiconductor thin film material is disclosed in which the thin film material substantially comprises a heteropyrene compound or derivative. In one embodiment, a thin film transistor comprises a layer of the organic semiconductor material. Further disclosed is a process for fabricating an organic thin-film transistor device, preferably by relative low-temperature sublimation or solution-phase deposition onto a substrate.

Claims

1. An article comprising a thin film of organic semiconductor material that comprises a 1,6-heteropyrene compound comprising heteroatoms at the 1,6-positions in the compound selected from the group consisting of oxygen and sulfur, wherein any of the positions on the compound'"'"'s heteropyrene aromatic nucleus can be optionally substituted, any two of which substituents can be combined into a ring, either saturated, unsaturated or aromatic fused ring.

2. The article of claim 1 wherein the article is a thin-film, field-effect transistor comprising a dielectric layer, a gate electrode, a source electrode and a drain electrode, and wherein the dielectric layer, the gate electrode, the thin film of organic semiconductor material, the source electrode, and the drain electrode are in any sequence as long as the gate electrode and the thin film of organic semiconductor material both contact the dielectric layer, and the source electrode and the drain electrode both contact the thin film of organic semiconductor material.

3. The article of claim 1, wherein the thin film of organic semiconductor material comprises a heteropyrene compound represented by the following Structure I:

4. The article of claim 3 wherein the substituents A, B, C, D, E, F, G, and H are independently selected from hydrogen and organic groups containing 1 to 12 carbon atoms, which groups may contain other atoms selected from the group consisting of such as oxygen, sulfur, nitrogen, phosphorous, or fluorine, which organic groups are selected not to have an undue adverse affect on the effective semiconductor properties of the heteropyrene compound.

5. The article of claim 3 wherein the substituents A, B, C, D, E, F, G, and H are each hydrogen or a substituted or unsubstituted alkyl, cycloalkyl, aryl, or alkylaryl substituent, and wherein optionally any two substituents in combination can may form a cycloalkyl or unsaturated ring or rings and/or any two of A and B, and/or D and F, can optionally form a fused benzo ring.

6. The article of claim 3 wherein the heteropyrene compound is substituted with at least one electron donating group.

7. The article of claim 3 wherein the substituents, if any, on the heteropyrene nucleus are all electron donating organic substituents.

8. The article of claim 6 wherein the at least one electron donating group is an alkyl group.

9. The article of claim 3, wherein in said structure A, B, C, D, E, F, G, and H are independently selected from H, CH₃, linear or branched C₂-C₄ alkyl alkenyl, alkoxy, or other electron donating organic group having 1 to 12 carbon atoms, which group may be substituted with an oxygen atom or carbonyl group.

10. The article of claim 3, wherein the heteropyrene compound is represented by one of following two structures, Structure II and III:

11. The article of claim 10, wherein in said Structure II and III, substituents B, C, D, F, G, and H are independently hydrogen or comprises an alkyl, cycloalkyl, or aryl substituent either substituted or unsubstituted.

12. The article of claim 10, wherein in said Structure II and III the substituents C, D, G, and H are hydrogen and A, B, E, and F are independently a substituent in which substituents A and B, and/or substituents E and F, can form an aromatic or non-aromatic fused ring or rings having 5 to 7 carbon atoms in each ring.

13. The article of claim 10, wherein in said Structure II and III the substituents A, B, C, D, E, F, G, and H may be independently selected from hydrogen and organic substituents selected from the group consisting of oxygen-containing organic substituents and/or a carbon-containing substituents, wherein oxygen-containing substituents have 1 to 12 carbon atoms and are selected from the group consisting of alkoxy, aryloxy, carboalkyl (—

C(═

O)R), carboaryl (—

C(═

O)Ar), carboalkoxy (—

C(═

O)OR), carboaryloxy (—

C(═

O)OAr), aryl or alkyl ketones (—

RC(═

O)R) or (—

ArC(═

O)Ar), all either substituted or unsubstituted all either substituted or unsubstituted, wherein R is a substituted or unsubstituted alky group having 1 to 11 carbon atoms and Ar is a substituted or unsubstituted aromatic group having 1 to 11 carbon atoms; and

wherein carbon-containing substituents are selected from the group consisting of alkyl groups of 1 to 12 carbons, cycloalkyl groups of 1 to 12 carbons, aryl groups of 6 to 12 carbons, alkaryl groups of 6 to 12 carbons, and heterocyclic groups having at least one heteroatom and 2 to 12 carbons;

all either substituted or unsubstituted;

wherein optionally two most adjacent groups on the heteropyrene nucleus may be joined to form a fused ring, either aliphatic or unsaturated, and A, B, E, and F may optionally be a fused ring that is aromatic, provided that creation of any ring will not unduly interfere with the functioning of the semiconductor thin film comprised of the compound.

14. The article of claim 1 wherein the thin film of organic semiconducting material is capable of exhibiting electron mobility greater than 0.001 cm²/Vs.

15. The article of claim 2, wherein the thin film transistor has an on/off ratio of a source/drain current of at least 10⁴.

16. The article of claim 2, wherein the gate electrode is adapted for controlling, by means of a voltage applied to the gate electrode, a current between the source and drain electrodes through the thin film of organic semiconductor material.

17. The article of claim 2 wherein the source, drain, and gate electrodes each independently comprise a material selected from doped silicon, metal, and a conducting polymer.

18. An electronic device selected from the group consisting of integrated circuits, active-matrix display, and solar cells comprising a multiplicity of thin film transistors according to claim 2.

19. The electronic device of claim 18 wherein the multiplicity of the thin film transistors is on a non-participating support that is optionally flexible.

20. A process for fabricating a thin film semiconductor device, comprising, not necessarily in the following order, the steps of:

(a) depositing, onto a substrate, a thin film of p-channel organic semiconductor material that substantially comprises the 1,6-heteropyrene compound of claim 1 and exhibits a field effect electron mobility that is greater than 0.01 cm²/Vs;

(b) forming a spaced apart source electrode and drain electrode,

wherein the source electrode and the drain electrode are separated by, and electrically connected with, the p-channel semiconductor film; and

.

(c) forming a gate electrode spaced apart from the organic semiconductor material.

21. The process of claim 20, wherein said compound is deposited on the substrate by sublimation or by solution-phase deposition and wherein the substrate has a temperature of no more than 250°

C. during deposition.

22. The process of claim 21 comprising, not necessarily in order, the following steps:

(a) providing a substrate;

(b) providing a gate electrode material over the substrate;

(c) providing a gate dielectric over the gate electrode material;

(d) depositing the thin film of p-channel organic semiconductor material over the gate dielectric; and

(e) providing a source electrode and a drain electrode contiguous to the thin film of p-channel organic semiconductor material.

23. The process of claim 22 wherein the steps are performed in the order listed and the substrate is flexible.

24. The process of claim 22 carried out in its entirety below a peak temperature of 100°

C.

25. An integrated circuit comprising a plurality of thin film transistors made by the process of claim 22.