Thermo-electric generator
A thermo-electric generator includes a semiconductor membrane with a phononic structure containing at least one P-N junction. The membrane is suspended between a first support designed to be coupled to a cold thermal source and a second support designed to be coupled to a hot thermal source. The structure for suspending the membrane has an architecture allowing the heat flux to be redistributed within the plane of the membrane.
1. A thermo-electric generator, comprising:
a semiconductor membrane containing a plurality of P-N junctions;
a first support;
a second support;
wherein the semiconductor membrane is suspended between the first support and the second support;
wherein the first support includes a first through opening and a second through opening;
a first electrically conducting pillar extending through the first through opening to make physical and electrical contact with a p-type region of the plurality of P-N junctions, said first electrically conducting pillar being electrically insulated from sidewalls of the first through opening; and
a second electrically conducting pillar extending through the second through opening to make physical and electrical contact with an n-type region of the plurality of P-N junctions, said second electrically conducting pillar being electrically insulated from sidewalls of the second through opening.
2. The thermo-electric generator of claim 1 , wherein the first support is configured to be coupled to a cold thermal source.
3. The thermo-electric generator of claim 1 , wherein the second support is configured to be coupled to a hot thermal source.
4. The thermo-electric generator of claim 1 , wherein the first and second electrically conducting pillars provide electrical output terminals at which a voltage potential is generated.
5. The thermo-electric generator of claim 1 , wherein the plurality of P-N junctions of the semiconductor membrane comprise plural strips alternately of a P conductivity type and an N conductivity type forming the plurality of P-N junctions coupled in series, wherein said p-type region comprises one of the strips of the P conductivity type and wherein said n-type region comprises one of the strips of the N conductivity type.
6. The thermo-electric generator of claim 1 , wherein the semiconductor membrane has a phononic structure comprising a lattice of inclusions of a compound different from the semiconductor material of the semiconductor membrane.
7. The thermo-electric generator of claim 6 , wherein the lattice of inclusions is symmetrical and comprises a first orientation direction comprising a first density of inclusions and a second orientation direction comprising a second density of inclusions lower than the first density, wherein the plurality of P-N junctions extend parallel to the second orientation direction.
8. The thermo-electric generator of claim 6 , wherein the lattice of inclusions is periodic with at least one repetition pitch less than a mean free path of thermal phonons and greater than a wavelength of the thermal phonons.
9. The thermo-electric generator of claim 8 , wherein the lattice of inclusions comprises a succession of various repetition pitches of increasing size.
10. The thermo-electric generator of claim 8 , wherein the lattice of inclusions comprises a succession of inclusions of increasing sizes.
11. The thermo-electric generator of claim 1 , wherein the semiconductor membrane is spaced by equal distances from the first and second supports.
12. The thermo-electric generator of claim 1 , wherein the first and second supports are rigid.
13. The thermo-electric generator of claim 1 , wherein the first and second supports are flexible.
14. The thermo-electric generator of claim 1 , fabricated as an integrated device.
15. The thermo-electric generator of claim 1 , wherein the semiconductor membrane is suspended from the first support by a plurality of thermally-conducting, but electrically insulating, pillars, wherein each pillar has a first end in contact with a P-N junction of said plurality of P-N junctions and a second end in contact with the first support.
16. The thermo-electric generator of claim 15 , wherein the plurality of thermally-conducting, but electrically insulating, pillars are in contact with alternating ones of the plurality of P-N junctions.
17. The thermo-electric generator of claim 1 , wherein the semiconductor membrane is suspended from the second support by a plurality of thermally-conducting, but electrically insulating, pillars, wherein each pillar has a first end in contact with a P-N junction of said plurality of P-N junctions and a second end in contact with the second support.
18. The thermo-electric generator of claim 17 , wherein the plurality of thermally-conducting, but electrically insulating, pillars are in contact with alternating ones of the plurality of P-N junctions.
19. The thermo-electric generator of claim 1 :
wherein the semiconductor membrane is suspended from the first support by a plurality of thermally-conducting, but electrically insulating, first pillars that are in contact with first alternating ones of the plurality of P-N junctions on a first side of the semiconductor membrane; and
wherein the semiconductor membrane is suspended from the second support by a plurality of thermally-conducting, but electrically insulating, second pillars that are in contact with second alternating ones of the plurality of P-N junctions on a second side of the semiconductor membrane.
20. The thermo-electric generator of claim 19 , wherein the first alternating ones of the plurality of P-N junctions are different from the second alternating ones of the plurality of P-N junctions.
21. A thermo-electric generator, comprising:
a semiconductor membrane containing a plurality of P-N junctions;
a first support;
a second support;
wherein the semiconductor membrane is suspended between the first support and the second support;
wherein the semiconductor membrane is suspended from the first support by a plurality of thermally-conducting first pillars, each first pillar having a first end in direct contact with first alternating ones of the plurality of P-N junctions on a first side of the semiconductor membrane and having a second end and further including an insulating layer for electrically insulating the second end of the first pillar from the first support; and
wherein the semiconductor membrane is suspended from the second support by a plurality of thermally-conducting second pillars, each second pillar having a first end in direct contact with second alternating ones of the plurality of P-N junctions on a second side of the semiconductor membrane and having a second end and further including an insulating layer for electrically insulating the second end of the second pillar from the second support.
22. The thermo-electric generator of claim 21 , wherein the first alternating ones of the plurality of P-N junctions are different from the second alternating ones of the plurality of P-N junctions.
23. The thermo-electric generator of claim 21 , further comprising:
a first through opening extending through the first support;
a second through opening extending through the first support;
a first electrically conducting pillar extending through the first through opening to make physical and electrical contact with a p-type region of the plurality of P-N junctions, said first electrically conducting pillar being electrically insulated from sidewalls of the first through opening; and
a second electrically conducting pillar extending through the second through opening to make physical and electrical contact with an n-type region of the plurality of P-N junctions, said second electrically conducting pillar being electrically insulated from sidewalls of the second through opening.
24. The thermo-electric generator of claim 23 , wherein the first and second electrically conducting pillars provide electrical output terminals at which a voltage potential is generated.
25. The thermo-electric generator of claim 21 , wherein the first support is configured to be coupled to a cold thermal source.
26. The thermo-electric generator of claim 21 , wherein the second support is configured to be coupled to a hot thermal source.
27. The thermo-electric generator of claim 21 , wherein the plurality of P-N junctions of the semiconductor membrane comprise plural strips alternately of a P conductivity type and an N conductivity type forming the plurality of P-N junctions coupled in series.
28. The thermo-electric generator of claim 21 , wherein the semiconductor membrane has a phononic structure comprising a lattice of inclusions of a compound different from the semiconductor material of the semiconductor membrane.
29. The thermo-electric generator of claim 28 , wherein the lattice of inclusions is symmetrical and comprises a first orientation direction comprising a first density of inclusions and a second orientation direction comprising a second density of inclusions lower than the first density, wherein the plurality of P-N junctions extend parallel to the second orientation direction.
30. The thermo-electric generator of claim 28 , wherein the lattice of inclusions is periodic with at least one repetition pitch less than a mean free path of thermal phonons and greater than a wavelength of the thermal phonons.
31. The thermo-electric generator of claim 30 , wherein the lattice of inclusions comprises a succession of various repetition pitches of increasing size.
32. The thermo-electric generator of claim 30 , wherein the lattice of inclusions comprises a succession of inclusions of increasing sizes.
33. The thermo-electric generator of claim 21 , wherein the semiconductor membrane is spaced by equal distances from the first and second supports.
34. The thermo-electric generator of claim 21 , wherein the first and second supports are rigid.
35. The thermo-electric generator of claim 21 , wherein the first and second supports are flexible.
36. The thermo-electric generator of claim 21 , fabricated as an integrated device.