Thin film transistor, method of manufacturing the same, and electronic device using the same

1. A thin film transistor comprising: a semiconductor layer; a source electrode and a drain electrode that each are connected to the semiconductor layer; an insulating layer that is formed adjacent to the semiconductor layer; and a gate electrode that faces the semiconductor layer across the insulating layer,

wherein the semiconductor layer includes an aggregate of semiconductor fine particles composed of a complex oxide, and

the complex oxide contains zinc and at least one selected from a group consisting of indium, gallium, and rhodium.

2. The thin film transistor according to claim 1 ,

wherein the complex oxide has a composition represented by InGao 3 (ZnO) m (m is a natural number of 10 or less), or ZnO.Rh 2 O 3 .

3. The thin film transistor according to claim 1 ,

wherein the semiconductor fine particles each are composed of a crystal of the complex oxide.

4. The thin film transistor according to claim 1 ,

wherein the semiconductor fine particles have an average particle diameter of not greater than 50 nm.

5. The thin film transistor according to claim 1 ,

wherein a surfactant is adsorbed on the surface of the semiconductor fine particles.

6. A method of manufacturing a thin film transistor including a semiconductor layer, the method comprising the steps of:

(i) forming a layer including an aggregate of semiconductor fine particles composed of a complex oxide by using a liquid that contains the semiconductor fine particles composed of the complex oxide; and

(ii) forming the semiconductor layer by subjecting the layer including the aggregate of the semiconductor fine particles to a heat treatment at a temperature of 150° C. or higher,

wherein the complex oxide contains zinc and at least one selected from a group consisting of indium, gallium, and rhodium.

7. The manufacturing method according to claim 6 ,

wherein the liquid contains a surfactant.

8. An electronic device comprising an electronic circuit,

wherein the electronic circuit includes the thin film transistor according to claim 1 .

9. The electronic device according to claim 8 ,

wherein the electronic device is a display device.

10. The electronic device according to claim 8 ,

wherein the electronic device is a mobile terminal.

11. The thin film transistor according to claim 1 ,

wherein the complex oxide has a composition represented by ZnO.Rh 2 O 3 .

12. The manufacturing method according to claim 6 ,

wherein the complex oxide has a composition represented by InGa0 3 (ZnO)m (m is a natural number of 10 or less), or ZnO.Rh 2 O 3 .

13. The manufacturing method according to claim 6 ,

wherein the complex oxide has a composition represented by ZnO.Rh 2 O 3 .