Device including vertically aligned two-dimensional material

1. A transistor comprising:

a substrate;

a two-dimensional material on the substrate, the two-dimensional material including at least one layer that is substantially vertically aligned to the substrate such that an edge of the at least one layer is on the substrate and the at least one layer extends substantially vertical to the substrate, each layer being a transition metal dichalcogenide monolayer;

a source electrode and a drain electrode connected to opposite ends of the two-dimensional material;

a gate insulation layer on the two-dimensional material between the source electrode and the drain electrode; and

a gate electrode on the gate insulation layer.

2. The transistor of claim 1 , wherein

the two-dimensional material includes a plurality of layers that are substantially vertically aligned to the substrate, and

the plurality of layers are parallel to each other.

3. The transistor of claim 1 , wherein

the two-dimensional material includes an upper surface and side surfaces,

the gate insulation layer and the gate electrode are on the upper surface and the side surfaces of the two-dimensional material.

4. A gas sensor comprising:

a substrate;

at least one two-dimensional material capable of adsorbing a desired gas,

the two-dimensional material including at least one layer that is substantially vertically aligned on the substrate such that an edge of the at least one layer is on the substrate and the at least one layer extends substantially vertical to the substrate,

each layer being a transition metal dichalcogenide monolayer; and

first and second electrodes connected to opposite ends of the two-dimensional material.

5. The gas sensor of claim 4 , further comprising:

a heater contacting the substrate, wherein

the heater is configured to remove the desired gas from being adsorbed onto the two-dimensional material by heating the at least one two-dimensional material.

6. The gas sensor of claim 4 , wherein

the at least one two-dimensional material includes a plurality of layers that are substantially vertically aligned to the substrate, and

the plurality of layers are parallel to each other.

7. A device comprising:

a substrate;

a two-dimensional material on the substrate, the two-dimensional material including at least one layer that has a width greater than a thickness and is arranged so the width of the at least one layer extends substantially vertical to the substrate, each layer being a transition metal dichalcogenide monolayer, a first electrode and a second electrode spaced apart from each other on the substrate, the first and second electrodes being connected to opposite ends of the two-dimensional material.

8. The device of claim 7 , further comprising:

a gate insulation layer on the two-dimensional material between the first electrode and the second electrode; and

a gate electrode on the gate insulation layer, wherein

the gate electrode is spaced apart from the first electrode and the second electrode.

9. The device of claim 7 , further comprising:

a heater connected to the substrate, wherein

the two-dimensional material is over the heater,

a gas is capable of adsorbing to the two-dimensional layer, and

the heater is configured to remove the gas from being adsorbed onto the two-dimensional material by heating the two-dimensional material.

10. The device of claim 7 , wherein

the two-dimensional material includes a plurality of layers that are substantially vertically aligned to the substrate, and

the plurality of layers are parallel to each other.