Photovoltaic devices with metal semiconductor alloy metallization

摘要

A photovoltaic device, such as a solar cell, having improved performance is provided. In one embodiment, the photovoltaic device includes a multimetal semiconductor alloy layer located on exposed portions of a front side surface of a semiconductor substrate. The multimetal semiconductor alloy layer includes at least a first elemental metal that forms an alloy with a semiconductor material, and a second elemental metal that differs from the first elemental metal and that does not form an alloy with a semiconductor material at the same temperature as the first elemental metal. The photovoltaic device further includes a copper-containing layer located atop the multimetal semiconductor alloy layer.

主权项

1. A photovoltaic device comprising:
a semiconductor substrate including a p-n junction with a p-type semiconductor portion and an n-type semiconductor portion one on top of the other, wherein an upper exposed surface of one of the semiconductor portions represents a front side surface of the semiconductor substrate; patterned antireflective coatings on the front side surface of the semiconductor substrate, wherein said patterned antireflective coatings protect some portions of the front side surface of the semiconductor substrate, while leaving other portions of the front side surface of the semiconductor substrate exposed, said other portions of the front side surface of the semiconductor substrate that are exposed form a grid pattern on the front side surface; a multimetal semiconductor alloy layer located on the other portions of the front side surface of the semiconductor substrate that are exposed, wherein said multimetal semiconductor alloy comprises at least a first elemental metal that forms an alloy with a semiconductor material at a first anneal temperature, and at least a second elemental metal that differs from the first elemental metal and that does not form an alloy with a semiconductor material at said first anneal temperature, and wherein said multimetal semiconductor alloy layer has a bottommost surface located below an uppermost surface of the front side surface of the semiconductor substrate; and a copper-containing layer in direct physical contact with the multimetal semiconductor alloy layer, wherein said copper-containing layer has sidewall surfaces that are vertically coincident to sidewall surfaces of said multimetal semiconductor alloy layer.