System and method for manufacturing photovoltaic structures with a metal seed layer
One embodiment of the present invention can provide a system for fabrication of a photovoltaic structure. The system can include a physical vapor deposition tool configured to sequentially deposit a transparent conductive oxide layer and a metallic layer on an emitter layer formed in a first surface of a Si substrate, without requiring the Si substrate to be removed from the physical vapor deposition tool after depositing the transparent conductive oxide layer. The system can further include an electroplating tool configured to plate a metallic grid on the metallic layer and a thermal annealing tool configured to anneal the transparent conductive oxide layer.
1. A method for fabricating a photovoltaic structure, the method comprising:
depositing, inside a physical vapor deposition chamber, a transparent conductive oxide layer on an emitter layer of the photovoltaic structure;
depositing, within the same physical vapor deposition chamber and without requiring the photovoltaic structure to be removed from the physical vapor deposition chamber after deposition of the transparent conductive oxide layer, a metallic seed layer on the transparent conductive oxide layer;
depositing, using a plating technique, a metallic grid on the metallic seed layer; and
simultaneously annealing the transparent conductive oxide layer the metallic grid, and the metallic seed layer.
2. The method of claim 1 , wherein the annealing is performed in an environment comprising:
air;
vacuum;
forming gas; or
inert gases.
3. The method of claim 1 , further comprising:
depositing, within the same physical vapor deposition chamber, a second transparent conductive oxide layer on a surface-field layer of the photovoltaic structure; and
depositing one or more metallic layers on the second transparent conductive oxide layer.
4. The method of claim 1 , wherein the physical vapor deposition chamber comprises a sputtering chamber or an evaporation chamber.
5. The method of claim 1 , further comprising depositing one or more metallic adhesive layers on the transparent conducive oxide layer, wherein the one or more metallic adhesive layers includes: Cu, Ni, Ag, Ti, Ta, W, TiN, TaN, WN, TiW, NiCr, or any combination thereof.
6. The method of claim 1 , wherein the transparent conductive oxide layer includes: indium-tin-oxide (ITO), aluminum-doped zinc-oxide (ZnO:Al), gallium-doped zinc-oxide (ZnO:Ga), tungsten-doped indium oxide (IWO), Zn—In—Sn—O (ZITO), or any combination thereof.
7. The method of claim 1 , wherein depositing the transparent conductive oxide layer is performed at a temperature lower than 100° C.
8. The method of claim 1 , wherein annealing the transparent conductive oxide layer and the one or more metallic layers comprises subjecting the photovoltaic structure to a temperature between 150° C. and 400° C.
9. The method of claim 8 , wherein annealing the transparent conductive oxide layer and the one or more metallic layers comprises subjecting the photovoltaic structure to the temperature for a time period between 5 seconds and 5 minutes.