Thermal lensing electrode in thermoelectric generators for improved performance
Exemplary thermoelectric devices and methods are disclosed herein. Thermoelectric generator performance is increased by the shaping isothermal fields within the bulk of a thermoelectric pellet, resulting in an increase in power output of a thermoelectric generator module. In one embodiment, a thermoelectric device includes a pellet comprising a semiconductor material, a first metal layer surrounding a first portion of the pellet, and a second metal layer surrounding a second portion of the pellet. The first and second metal layers are configured proximate to one another about a perimeter of the pellet. The pellet is exposed at the perimeter. And the perimeter is configured at a sidewall height about the pellet to provide a non-linear effect on a power output of the thermoelectric device by modifying an isotherm surface curvature within the pellet. The device also includes a metal container thermally and electrically bonded to the pellet.
1. A method of making a thermoelectric device, comprises:
metalizing a plurality of semiconductor pellets with one or more layers of metal;
removing a portion of the metal layers about perimeters of the semiconductor pellets to create a gap with each of the semiconductor pellets that exposes the semiconductor pellets;
forming a substrate with a plurality of cups from copper;
electroplating the cups with nickel;
coating a portion of the cups with solder;
placing each respective pellet of the plurality of pellets in a respective cup of the plurality of the cups such that a sidewall height of each cup matches a gap location of its respective pellet to provide a non-linear effect on a power output of the thermoelectric device by modifying isotherm surface curvatures within the pellets; and
curing the solder to adhere the pellets to the cups to form the thermoelectric device.
2. The method of claim 1 , further comprising:
configuring the isotherm surface curvature within each pellet to increase an effective surface area of a thermoelectric effect within a volume of each pellet via heat injection through the sidewalls of each pellet.
3. The method of claim 1 , further comprising:
electrically isolating remaining portions of the metal layers of each pellet from one another that result from removing the portion of the metal layers about the perimeters of the semiconductor pellets.
4. The method of claim 1 , further comprising:
configuring each of the pellets with beveled edges proximate to its perimeter to electrically isolate remaining portions of the metal layers of each pellet from one another that result from removing the portion of the metal layers about the perimeters of the semiconductor pellets.
5. The method of claim 1 , further comprising:
configuring the metal layers with a higher thermal conductivity than each of the pellets.
6. The method of claim 5 , further comprising:
configuring at least one of the metal layers with copper.
7. The method of claim 1 , further comprising:
configuring each of the pellets in a shape that is operable to increase a thermal lensing effect of the thermoelectric device.
8. The method of claim 7 , wherein:
the shape is a cuboid.
9. The method of claim 7 , wherein:
the shape is a cylinder.