Optoelectronic device
An optoelectronic device is disclosed. The disclosed optoelectronic device includes an oxide semiconductor layer and a semiconducting two-dimensional (2D) material layer forming a stack structure with the oxide semiconductor layer.
1. An optoelectronic device comprising:
an oxide semiconductor layer;
a semiconducting two-dimensional (2D) material layer in a stacked configuration with the oxide semiconductor layer;
an electrode electrically connected to the oxide semiconductor layer or to the semiconducting 2D material layer, the semiconducting 2D material layer being substantially entirely confined within an area defined by a surface of the oxide semiconductor layer;
an insulating layer; and
a substrate;
wherein the semiconducting two-dimensional (2D) material layer, the oxide semiconductor layer and the insulating layer are sequentially interposed between the electrode and the substrate.
2. The optoelectronic device of claim 1 , wherein the oxide semiconductor layer and the semiconducting 2D material layer form a hetero structure.
3. The optoelectronic device of claim 1 , wherein the semiconducting 2D material layer comprises a transition-metal dichalcogenide material.
4. The optoelectronic device of claim 3 , wherein the semiconducting 2D material layer comprises at least one of molybdenum sulfide (MoS 2 ), molybdenum selenide (MoSe 2 ), tungsten sulfide (WS 2 ), and tungsten selenide (WSe 2 ).
5. The optoelectronic device of claim 1 , wherein the semiconducting 2D material layer has a band gap of about 1.2 eV to about 1.8 eV.
6. The optoelectronic device of claim 3 , wherein the oxide semiconductor layer comprises at least one of amorphous indium gallium zinc oxide (a-IGZO) and zinc oxide (ZnO).
7. The optoelectronic device of claim 6 , wherein the oxide semiconductor layer has a band gap of about 3.0 eV or more.
8. The optoelectronic device of claim 7 , wherein the semiconducting 2D material layer has a band gap of about 1.2 eV to about 1.8 eV.
9. The optoelectronic device of claim 1 , wherein the oxide semiconductor layer comprises at least one of amorphous indium gallium zinc, oxide (a-IGZO) and zinc oxide (ZnO).
10. The optoelectronic device of claim 9 , wherein the oxide semiconductor layer has a band gap of about 3.0 eV or more.
11. The optoelectronic device of claim 10 , wherein the semiconducting 2D material layer has a band gap of about 1.2 eV to about 1.8 eV.
12. The optoelectronic device of claim 1 , wherein the semiconducting 2D material layer has a band gap of about 1.2 eV to about 1.8 eV, and
the oxide semiconductor layer has a band gap of about 3.0 eV or more.
13. The optoelectronic device of claim 1 , wherein the semiconducting 2D material layer is configured to absorb light in a visible light region, and
the oxide semiconductor layer is configured to absorb light in an ultraviolet (UV) region.
14. The optoelectronic device of claim 1 , wherein the semiconducting 2D material layer is on the oxide semiconductor layer, and
the electrode comprises a plurality of upper electrodes in a plurality of regions on the semiconducting 2D material layer, the plurality of upper electrodes being spaced apart from each other.
15. The optoelectronic device of claim 1 , further comprising, below the oxide semiconductor layer, a lower electrode and the insulating layer covering the lower electrode and forming a phototransistor.
16. The optoelectronic device of claim 1 , wherein the semiconducting 2D material layer is on the oxide semiconductor layer, and
the electrode comprises a plurality of upper electrodes via the semiconducting 2D material layer in a plurality of regions,
wherein the upper electrodes are spaced apart from each other and are in direct contact with the oxide semiconductor layer.
17. The optoelectronic device of claim 16 , further comprising, below the oxide semiconductor layer, a lower electrode and the insulating layer covering the lower electrode and forming a phototransistor.
18. The optoelectronic device of claim 1 , wherein the electrode on upper and lower sides of the stack configuration includes the oxide semiconductor layer and the semiconducting 2D material layer and is configured to form any one of a phototransistor, a photodetector and an image sensor including a 2D array of optoelectronic devices.
19. The optoelectronic device of claim 1 , wherein the oxide semiconductor layer is configured as a channel layer through which carriers generated when light is absorbed by the semiconducting 2D material layer can move.
20. The optoelectronic device of claim 19 , wherein the semiconducting 2D material layer is configured to absorb light in a visible light region, and
the oxide semiconductor layer is configured to absorb light in a UV region.