Three terminal thin film photovoltaic module and their methods of manufacture
View Patent ↗Thin film photovoltaic devices are generally provided having three terminals. In one embodiment, the thin film photovoltaic device can include a first submodule defined by a first plurality of photovoltaic cells between a first dead cell and a first terminal cell; a second submodule defined by a second plurality of photovoltaic cells between a second dead cell and a second terminal cell; and a joint bus bar electrically connected to the first dead cell and the second dead cell. The first dead cell is adjacent to the second dead cell, with the first dead cell being separated from the second dead cell via a separation scribe. Methods are also generally provided for forming a thin film photovoltaic device.
1. A thin film photovoltaic device, comprising:
a first submodule defined by a first plurality of photovoltaic cells between a first dead cell and a first terminal cell;
a second submodule defined by a second plurality of photovoltaic cells between a second dead cell and a second terminal cell, wherein the first dead cell is adjacent to the second dead cell, the first dead cell being separated from the second dead cell via a separation scribe; and,
a joint bus bar electrically connected to the first dead cell and the second dead cell.
2. The device as in claim 1 , wherein the separation scribe is filled with a nonconductive material.
3. The device as in claim 2 , wherein the separation scribe extends through an absorber layer, a window layer, and a transparent conductive oxide layer.
4. The device as in claim 1 , wherein the separation scribe is filled with a conductive material.
5. The device as in claim 4 , wherein the separation scribe electrically connects a back contact to a transparent conductive layer.
6. The device as in claim 1 , wherein the separation scribe extends through a back contact layer.
7. The device as in claim 6 , wherein the separation scribe further extends through an absorber layer.
8. The device as in claim 7 , wherein the separation scribe further extends through a transparent conductive oxide layer.
9. The device as in claim 1 , further comprising:
a first terminal electrically connected to the first terminal cell; and,
a second terminal electrically connected to the second terminal cell.
10. The device as in claim 9 , further comprising:
a conductive link electrically connecting the first terminal to the second terminal, wherein the conductive link is electrically isolated from the first dead cell and the second dead cell.
11. The device as in claim 1 , wherein photovoltaic cells of the first and second submodules are separated from their adjacent photovoltaic cells by a first isolation scribe, a series connecting scribe, and a second isolation scribe.
12. The device as in claim 1 , wherein each photovoltaic cell of the first and second submodules comprises a transparent conductive oxide layer on a transparent substrate; a window layer on the transparent conductive oxide layer, and an absorber layer on the window layer; and wherein the absorber layer comprises cadmium telluride.
13. A method of forming a thin film photovoltaic device according to claim 9 , the method comprising:
attaching a first terminal to a first terminal cell to electrically connect the first terminal to the first terminal cell, wherein the first terminal cell is positioned on one end of a first submodule defined by a first plurality of photovoltaic cells between the first terminal cell and a first dead cell;
attaching a joint bus bar to the first dead cell and to a second dead cell to electrically connect the first dead cell and the second dead cell, wherein the second dead cell is positioned on one end of a second submodule defined by a second plurality of photovoltaic cells between the second dead cell and a second terminal, wherein the first dead cell and the second dead cell are separated via a separation scribe; and,
attaching a second terminal to the second terminal cell to electrically connect the second terminal to the second terminal cell.
14. The method as in claim 13 , further comprising:
forming the separation scribe to remove an absorber layer, an n-type window layer, and a transparent conductive oxide layer.
15. The method as in claim 14 , further comprising:
filling the separation scribe with a nonconductive material.
16. The method as in claim 13 , further comprising:
forming the separation scribe to remove an absorber layer while leaving a transparent conductive oxide layer.
17. The method as in claim 16 , filling the separation scribe with a conductive material.
18. The method as in claim 13 , further comprising:
forming the separation scribe to remove a back contact layer and an absorber layer; and, leaving the separation scribe unfilled in the device.
19. The method as in claim 18 , wherein the separation scribe is formed via removing back contact layer, the absorber layer, a window layer, and a transparent conductive oxide layer.
20. The method as in claim 13 , wherein the separation scribe is formed via a laser.