Solar cells with plated back side surface field and back side electrical contact and method of fabricating same

摘要

The present disclosure provides a method of forming a back side surface field of a solar cell without utilizing screen printing. The method includes first forming a p-type dopant layer directly on the back side surface of the semiconductor substrate that includes a p/n junction utilizing an electrodeposition method. The p/n junction is defined as the interface that is formed between an n-type semiconductor portion of the substrate and an underlying p-type semiconductor portion of the substrate. The plated structure is then annealed to from a P++ back side surface field layer directly on the back side surface of the semiconductor substrate. Optionally, a metallic film can be electrodeposited on an exposed surface of the P++ back side surface layer.

主权项

1. A method of fabricating a solar cell comprising:
providing a semiconductor substrate of a first thickness and comprising a single semiconductor material layer including a p-type semiconductor portion and an overlying n-type semiconductor portion, wherein an exposed surface of the p-type semiconductor portion defines a back side surface of the semiconductor substrate and wherein an exposed surface of the n-type semiconductor portion defines a front side surface; forming a p-type dopant layer directly on and in direct physical contact with said back side surface of said p-type semiconductor portion of said semiconductor substrate, wherein said p-type dopant layer is formed by electroplating at least one p-type dopant atom selected from the group consisting of boron, gallium and indium from an electroplating bath; and thermal annealing said semiconductor substrate and said p-type dopant layer to convert a portion of the p-type semiconductor portion of the semiconductor substrate into a P++ doped semiconductor back side surface field layer, wherein during said thermally annealing said p-type dopant layer is completely consumed and said semiconductor substrate has a second thickness that is greater than the first thickness.