High efficiency thermoelectric materials and devices
Growth of thermoelectric materials in the form of quantum well superlattices on three-dimensionally structured substrates provide the means to achieve high conversion efficiency of the thermoelectric module combined with inexpensiveness of fabrication and compatibility with large scale production. Thermoelectric devices utilizing thermoelectric materials in the form of quantum well semiconductor superlattices grown on three-dimensionally structured substrates provide improved thermoelectric characteristics that can be used for power generation, cooling and other applications.
1. A thermoelectric material comprising:
a structured substrate having a plurality of elongated pores, each elongated pore being defined by walls of the pore consisting of the material of the substrate and the walls of the pores extending from at least one face of the substrate in a direction substantially normal to the face of the substrate, and
a semiconductor quantum well superlattice of at least two layers of semiconductor material, having dissimilar characteristics from each other and being deposited directly on each other, coating a wall of each of the plurality of elongated pores of said structured substrate.
2. The thermoelectric material of claim 1 , wherein one of the semiconductor materials is Bi 2 Te 3 and the other semiconductor material is Sb 2 Te 3 .
3. The thermoelectric material of claim 1 , wherein each layer of the semiconductor quantum well superlattice has a thickness in the range of 10 Å to 50 Å.
4. The thermoelectric material of claim 1 , wherein the structured substrate is of the material Si.
5. The thermoelectric material of claim 1 , wherein each of the plurality of pores has a pore aspect ratio in the range of 10 to 1000 and a pore diameter in the range of 0.2 μm to 10 μm.
6. A thermoelectric material comprising:
a structured substrate having a plurality of elongated pores, each elongated pore being defined by walls of the pore consisting of the material of the substrate and the walls of the pores extending from at least one face of the substrate in a direction substantially normal to the face of the substrate,
a buffer layer coating a wall of each of the plurality of elongated pores of said structured substrate, and
a semiconductor quantum well superlattice of at least two layers of semiconductor material, having dissimilar characteristics from each other and being deposited directly on each other, coating the buffer layer.
7. The thermoelectric material of claim 6 , wherein one of the semiconductor materials is Bi 2 Te 3 and the other semiconductor material is Sb 2 Te 3 .
8. The thermoelectric material of claim 6 , wherein each layer of the semiconductor quantum well superlattice has a thickness in the range of 10 Å to 50 Å.
9. The thermoelectric material of claim 6 , wherein the structured substrate is of the material Si.
10. The thermoelectric material of claim 6 , wherein each of the plurality of pores has a pore aspect ratio in the range of 10 to 1000 and a pore diameter in the range of 0.2 μm to 10 μm.