Granted Patent B2

US 7,638,793 · App. 10/586,149 · Granted Dec 29, 2009

Abstract

Claims (21)

1. An n-channel or ambipolar field-effect transistor including an organic semiconductive layer having an electron affinity EA semicond ; and an organic gate dielectric layer forming an interface with the semiconductive layer; characterised in that the bulk concentration of trapping groups in the gate dielectric layer is less than 10 18 cm −3 , where a trapping group is a group having (i) an electron affinity EA x greater than or equal to EA semicond and/or (ii) a reactive electron affinity EA rxn greater than or equal to (EA semicond. −2 eV).

2. A transistor according to claim 1 , wherein the transistor is an ambipolar field-effect transistor.

3. A transistor according to claim 1 wherein EA semicond. is greater than or equal to 2 eV.

4. A transistor according to claim 3 wherein EA semicond. is in the range of from 2 eV to 4 eV.

5. A transistor according to claim 1 wherein the gate dielectric layer comprises an organic insulating material and the organic insulating material does not contain a repeat unit or residue unit comprising a trapping group.

6. A transistor according to claim 1 , wherein the insulating material does not contain a repeat unit or residue unit comprising a group having (i) an electron affinity EA x greater than or equal to 3 eV and/or (ii) a reactive electron affinity EA rxn greater than or equal to 0.5 eV.

7. A transistor according to claim 6 wherein the insulating material does not contain a repeat unit or residue unit comprising a quinone, aromatic —OH, aliphatic —COOH, aromatic —SH, or aromatic —COOH group.

8. A transistor according to claim 1 , wherein the insulating material contains one or more groups selected from alkene, alkylene, cycloalkene, cycloalkylene, siloxane, ether oxygen, alkyl, cycloalkyl, phenyl, and phenylene groups.

9. A transistor according to claim 1 wherein the insulating material comprises an insulating polymer.

10. A transistor according to claim 9 , wherein the insulating polymer is selected from the group consisting of substituted and unsubstituted poly(siloxanes) and copolymers thereof; substituted and unsubstituted poly(alkenes) and copolymers thereof; substituted and unsubstituted poly(styrenes) and copolymers thereof; and substituted and unsubstituted poly(oxyalkylenes) and copolymers thereof.

11. A transistor according to claim 10 , wherein the backbone of the insulating polymer comprises a repeat unit comprising —Si(R) 2 —O—Si(R) 2 — where each R independently is methyl or substituted or unsubstituted phenyl.

12. A transistor according to claim 9 , wherein the insulating polymer is crosslinked.

13. A transistor according to claim 1 wherein the organic semiconductive layer comprises a semiconductive polymer.

14. A transistor according to claim 1 wherein the organic semiconductive layer comprises a semiconductive oligomer.

15. A transistor according to claim 1 wherein the organic semiconductive layer comprises a semiconductive small molecule.

16. A method for making a transistor as defined in claim 1 .

17. Use of a transistor according to claim 1 for n-channel conduction in an n-channel or ambipolar field effect transistor.

18. Use of an organic gate insulating material that does not contain any chemical groups having (i)EA x greater than or equal to 3 eV and/or (ii)EA rxn greater than or equal to 0.5 eV, for n-channel conduction.

19. Use according to claim 18 , wherein the insulating material does not contain any chemical groups having (i)EA x greater than or equal to 2 eV and/or (EA rxn ) greater than or equal to 0 eV.

20. A circuit, complementary circuit, or logic circuit including a transistor as defined in claim 1 .

21. A method for making a circuit, complementary circuit, or logic circuit as defined in claim 20 .

Assignments (6)