Electron injection-controlled microcavity plasma device and arrays
View Patent ↗An embodiment of the invention is a microcavity plasma device that can be controlled by a low voltage electron emitter. The microcavity plasma device includes driving electrodes disposed proximate to a microcavity and arranged to contribute to generation of plasma in the microcavity upon application of a driving voltage. An electron emitter is arranged to emit electrons into the microcavity upon application of a control voltage. The electron emitter is an electron source having an insulator layer defining a tunneling region. The microplasma itself can serve as a second electrode necessary to energize the electron emitter. While a voltage comparable to previous microcavity plasma devices is still imposed across the microcavity plasma devices, control of the devices can be accomplished at high speeds and with a small voltage, e.g., about 5V to 30V in preferred embodiments.
1. A microcavity plasma device, comprising:
a microcavity in material;
driving electrodes disposed proximate to said microcavity and arranged to contribute to generation of plasma in the microcavity upon application of driving voltage;
an electron emitter including a dielectric film through which electrons tunnel to enter said microcavity.
2. The device of claim 1 , wherein said dielectric film is spaced at a predetermined distance from said microcavity to protect the emission region from plasma generated in said microcavity.
3. The device of claim 2 , wherein said predetermined distance is 30-100 μm.
4. The device of claim 3 , wherein said electron emitter comprises:
an electron source region,
a dielectric layer defining the tunneling region;
wherein the tunneling region and the microcavity are arranged such that electrons are emitted into the microcavity upon application of the control voltage.
5. The device of claim 4 , further comprising dielectric to isolate said driving electrodes from said microcavity.
6. The device of claim 1 , wherein said electron emitter comprises:
an electron source region,
a dielectric layer defining the tunneling region;
wherein the tunneling region and the microcavity are arranged such that electrons are emitted into the microcavity upon application of the control voltage.
7. The device of claim 6 , further comprising dielectric to isolate said driving electrodes from said microcavity.
8. An array of microcavity plasma devices comprising a plurality of microcavity plasma devices according to claim 7 .
9. The device of claim 1 , wherein said electron emitter comprises a semiconductor/oxide film electron emitter having the oxide film tunneling region arranged such that electrons are emitted into the microcavity upon application of the control voltage.
10. The device of claim 9 , wherein said tunneling region is disposed ˜30-100 μm from said microcavity.
11. The device of claim 9 , further comprising dielectric to isolate said driving electrodes from said microcavity.
12. An array of microcavity plasma devices comprising, a plurality of microcavity plasma devices according to claim 9 .
13. The device of claim 1 , wherein said electron emitter comprises a metal/insulator film electron emitter having a tunneling region arranged such that electrons are emitted into the microcavity upon application of the control voltage.
14. The device of claim 13 , wherein said tunneling region is disposed ˜30-100 μm from said microcavity.
15. The device of claim 13 , further comprising dielectric to isolate said driving electrodes from said microcavity.
16. An array of microcavity plasma devices comprising a plurality of microcavity plasma devices according to claim 15 .
17. An array of microcavity plasma devices comprising a plurality of microcavity plasma devices of claim 1 .
18. A microcavity plasma device, comprising:
microcavity plasma means for producing and containing a plasma in a microcavity defined by the microcavity plasma means; and
electron emitter means for controlling the plasma by the controlled injection of electrons into the microcavity.
19. A method for controlling a microcavity plasma device, the method comprising steps of:
applying a driving voltage to a microcavity plasma device;
controlling plasma in the microcavity plasma device with the controlled injection of electrons from an electron emitter into a microcavity of the plasma device with a control voltage that is substantially smaller than the driving voltage.
20. The method of claim 19 , wherein said control voltage is within the range of approximately 5 to 30V.