Photovoltaic cells, modules and methods of making same
A photovoltaic cell has electrodes, p- and n-junctions, and a heat sink. The heat sink is on a side of the cell opposite to the light-receiving side of the photovoltaic cell. The photovoltaic cell may also have heat-conducting channels within an interior of the photovoltaic cell that conduct heat from the interior of the photovoltaic cell to the heat sink. The heat sink can remove heat caused by light absorbed by the photovoltaic cell but not converted to electricity as well as heat generated by resistance to high current passing through electrodes of the photovoltaic cell. A module formed of such cells can exhibit greater energy conversion efficiency as a result of the ability to dissipate the heat. A method of making a solar cell or module involves e.g. laminating a heat sink to a photovoltaic cell as described above.
1. A photovoltaic cell having
a) a light-receiving surface and a surface opposite the light-receiving surface,
b) a semiconductor body comprising a first region, a second region not the same as the first region, and a junction at an interface of the first region and the second region,
c) a first electrode electrically connected to the first region and a second electrode electrically connected to the second region of the photovoltaic cell,
d) a heat sink at the surface opposite the light-receiving surface, and
e) heat-conducting channels in thermal communication with the heat sink and extending into the semiconductor body.
2. A photovoltaic cell according to claim 1 wherein the heat-conducting channels extend into at least one of the first region and the second region.
3. A photovoltaic cell according to claim 1 wherein the semiconductor body further comprises a third region different from the first region and the second region.
4. A photovoltaic cell according to claim 3 wherein the heat-conducting channels extend into the third region.
5. A photovoltaic cell according to claim 4 wherein the heat-conducting channels also extend into at least one of the first and the second regions.
6. A photovoltaic cell according to claim 4 wherein the heat-conducting channels do not extend into the first region, and the heat conducting channels do not extend into the second region.
7. A photovoltaic cell according to claim 5 wherein the first region is a p-type region, the second region is an n-type region, and the third region is an i-type region.
8. A photovoltaic cell according to claim 6 wherein first region is a p-type region, the second region is an n-type region, and the third region is a portion of a silicon substrate from which the cell is formed.
9. A photovoltaic cell according to claim 1 wherein the junction is a heterojunction.
10. A photovoltaic cell according to claim 1 further comprising heat conducting platforms positioned between the heat conducting channels and the heat sink and in thermal communication with the heat conducting channels and the heat sink.
11. A photovoltaic cell according to claim 1 wherein the heat conducting channels have an electrically insulating layer between the heat conducting channels and material of the surrounding body of the photocell.
12. A photovoltaic cell according to claim 1 wherein the heat conducting channels are formed of a metal or an alloy.
13. A photovoltaic cell according to claim 1 wherein the heat sink is formed of a thermally conductive polymer.
14. A photovoltaic cell according to claim 1 wherein the heat conducting channels are formed of a metal or alloy and the heat sink is formed of a thermally conductive polymer.