Method for producing an organic field effect transistor and an organic field effect transistor

1. A method for producing an organic field effect transistor, the method comprising steps of:

providing a gate electrode, and providing a gate insulator on the gate electrode, wherein the gate insulator is assigned to the gate electrode for electrical insulation on a substrate;

depositing a first organic semiconducting layer on the gate insulator;

depositing a first doping material layer on at least a portion of the first organic semiconducting layer;

depositing a first electrode and an electrode insulator on at least a portion of the first doping material layer, wherein the electrode insulator is arranged on the first electrode for electrical insulation;

depositing a second organic semiconducting layer on the first organic semiconducting layer and the electrode insulator,

depositing a second doping material layer on the second organic semiconducting layer; and

depositing a second electrode at least partially on the second doping material layer.

2. The method according to claim 1 , wherein at least one of the step of depositing the first electrode and the electrode insulator, the step of depositing the first doping material layer, the step of depositing the second electrode, and the step of depositing the second doping material layer comprises a step of photo-lithographic structuring on the first and the second organic semiconducting layer, respectively.

3. The method according to claim 1 , wherein at least one of the first doping material layer and the second doping material layer is deposited by physical vapour deposition.

4. The method according to claim 1 , wherein at least one of the first doping material layer and the second doping material layer comprises a pure electrical dopant material, respectively.

5. The method according to claim 1 , wherein at least one of the first doping material layer and the second doping material layer comprises a matrix material including an electrical dopant material, respectively.

6. The method according to claim 5 , wherein the matrix material is an organic semiconducting material.

7. The method according to claim 1 , wherein the first and second organic semiconducting layers comprise the same organic matrix material.

8. The method according to claim 1 , wherein the first electrode comprises first sub-electrode portions and the second electrode comprises second sub-electrode portions, the plurality of sub-electrode portions being arranged in separated groups of overlapping sub-electrode portions, wherein each of the separated groups of overlapping sub-electrode portions is generated with at least one first sub-electrode portion overlapping with at least one second sub-electrode portion.

9. The method according to claim 8 , wherein at least one of the first sub-electrode portions and the second sub-electrode portions are at least partially in direct contact with the first doping material layer or the second doping material layer, respectively.

10. The method according to claim 1 , wherein the step of depositing the first electrode and the electrode insulator comprises:

depositing a first photoresist layer on the first organic semiconducting layer and/or the first doping material layer, if applicable;

defining an electrode area for the first electrode by patterning the first photoresist layer, thereby providing a first photoresist pattern;

depositing a first conductive layer on the first photoresist pattern;

depositing an insulating layer on the first conductive layer; and

removing the first photoresist pattern in a lift-off process, thereby generating the first electrode and the electrode insulator.

11. The method according to claim 1 , wherein the step of depositing the second electrode comprises:

depositing a second photoresist layer on the first organic semiconducting layer, on the electrode insulator, and on the second doping material layer, if applicable;

defining an electrode area for the second electrode by patterning the second photoresist layer, thereby providing a second photoresist pattern;

depositing a second unpatterned organic semiconducting layer on the second photoresist pattern;

depositing a second conductive layer on the second unpatterned organic semiconducting layer; and

removing the second photoresist pattern in a lift-off process, thereby generating the second organic semiconducting layer and the second electrode.

12. An organic field effect transistor, comprising:

a first electrode and a second electrode, the first and second electrodes providing a source electrode and a drain electrode;

a gate electrode;

a gate insulator provided between the gate electrode and the first electrode;

an electrode insulator provided between the first and the second electrode;

a first organic semiconducting layer provided between the gate insulator and the first electrode;

a second organic semiconducting layer provided between the first organic semiconducting layer and the second electrode;

a first doping material layer which is provided between the first electrode and the first organic semiconducting layer and which is at least partially in direct contact with the first electrode; and

a second doping material layer which is provided between the second electrode and the second organic semiconducting layer and which is at least partially in direct contact with the second electrode.

13. The transistor according to claim 12 , wherein the first and second organic semiconducting layers are configured to transport charge carriers of the same type.

14. The transistor according to claim 12 , wherein the first electrode comprises first sub-electrode portions and the second electrode comprises second sub-electrode portions, the plurality of sub-electrode portions being arranged in separated groups of overlapping sub-electrode portions, wherein each of the separated groups of overlapping sub-electrode portions comprises at least one first sub-electrode portion overlapping with at least one second sub-electrode portion.

15. The transistor according to claim 14 , wherein at least one of the first doping material layer and the second doping material layer is at least partially in direct contact with the first sub-electrode portions or the second sub-electrode portions, respectively.

16. An electronic switching device, comprising an organic field effect transistor according to claim 12 .