Claims
- 1. A method for manufacturing microminiature thermionic converters comprising the steps of:depositing a first electrode layer comprising a first material selected from the group consisting of BaO, SrO, CaO, Sc2O3, other oxides, and a mixture of BaSrCaO, Sc2O3 and metal, and any combinations thereof, and having a first work function; depositing a dielectric oxide spacer layer; depositing a second electrode layer comprising a second material selected from the group consisting of BaO, SrO, CaO, Sc2O3, other oxides, and a mixture of BaSrCaO, Sc2O3 and metal; and any combinations thereof having a second work function that is different from the first work function; and removing matter from the dielectric oxide spacer layer thereby forming an interelectrode gap.
- 2. The method of claim 1 wherein the dielectric oxide spacer layer comprises material selected from the group consisting of SiO2 and Si3N4 and combinations thereof.
- 3. The method of claim 2 wherein the step of removing matter from the dielectric oxide spacer layer comprises a technique selected from the group consisting ofsteps comprising masking at least part of the first electrode layer, masking at least part of the second electrode layer, masking at least two parts of the spacer layer, and etching out an interelectrode gap bound on opposite sides by unetched portions of the spacer layer; steps comprising sputtering particles to disrupt crystal structure in a part of the spacer layer thereby causing the crystal structure to disintegrate in that part of the spacer layer and leave an interelectrode gap; and steps comprising utilizing etching vias cut into at least one of the electrode layers to permit etchant to enter the spacer layer and remove a portion of the spacer layer between the first and second electrode layers, leaving an interelectrode gap.
- 4. The method of claim 3 wherein part of the spacer layer remains after removal of a portion of the spacer layer, and said part of the spacer layer remaining consists of no more than two separate spacing elements.
- 5. The method of claim 3 wherein part of the spacer layer remains after removal of a portion of the spacer layer, and said part of the spacer layer remaining consists of a plurality of spacing elements sufficiently few in number and of sufficiently low aggregate cross sectional area that, in a microminiature thermionic converter so manufactured, when operating, the ratio of watts of thermal conversion to watts of thermal conductivity losses, including losses resulting from flow of thermal energy between the first and second electrode layers via spacing elements, is greater than about 0.15.
- 6. A method of manufacturing microminiature thermionic converters comprising the steps of:depositing a first substrate comprising a dielectric; depositing a second substrate comprising material selected from the group consisting of dielectric and semiconductor; forming in the second substrate a recess comprising at least one wall and a floor boundary; depositing a first conductor having a substantially flat surface in the first substrate; depositing a second conductor having a substantially flat surface in the second substrate so the substantially flat surface extends through the floor boundary and into the recess; coating the first substantially flat surface with a first coating material; coating the second substantially flat surface with a second coating material different from the first coating material; assembling the first substrate and the second substrate together so that the first substantially flat surface and the second substantially flat surface are substantially parallel and opposite each other, with a space therebetween.
- 7. The method of claim 6 wherein the first coating material has a first work function and is selected from the group consisting of BaO, SrO, CaO, Sc2O3, and a mixture of BaSrCaO, Sc2O3 and metal, and any combinations thereof, and the second coating is different from the first coating and has a second work function different from the first work function.
- 8. The method of claim 7 wherein the second coating is selected from the group consisting of BaO, SrO, CaO, Sc2O3, and a mixture of BaSrCaO, Sc2O3 and metal, and any combinations thereof.
Parent Case Info
This application is a continuation-in-part of application Ser. No. 09/257,335, now US Pat. No. 6,294,858 filed Feb. 25, 1999, which in turn claimed the benefit of U.S. Provisional Application No. 60/076,010, filed Feb. 26, 1998, both of which are herein incorporated by reference in their entirety. Various other patent applications are likewise herein incorporated in their entirety, as noted elsewhere in this disclosure.
Government Interests
This invention was made with support from the United States Government under Contract DE-AC04-96AL85000 awarded by the U.S. Department of Energy. The Government has certain rights in this invention.
US Referenced Citations (8)
Non-Patent Literature Citations (3)
Entry |
King, et al. “Thermionic Modules,” pending patent application filed Jun. 28, 2001, incorporated by reference. |
King, et al. “Microminiature Thermionic Converters,” pending patent application filed Jun. 28, 2001, incorporated by reference. |
Zavadil, et al. “Low Work Function Materials for Microminiature Energy Conversion and Recovery Applications,” pending patent application filed Jun. 28, 2001, Ser. No. 09/257,336, incorporated by reference. |
Provisional Applications (1)
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Number |
Date |
Country |
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60/076010 |
Feb 1998 |
US |
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
09/257335 |
Feb 1999 |
US |
Child |
09/895372 |
|
US |