Leave-in etch mask for foil-based metallization of solar cells

A solar cell, comprising:

• a substrate having a back surface and an opposing light-receiving surface;
• a plurality of N-type and P-type semiconductor regions disposed in or above the back surface of the substrate;
• a conductive contact structure disposed on the plurality of N-type and P-type semiconductor regions, the conductive contact structure comprising metal foil portions in alignment with corresponding ones of the N-type and P-type semiconductor regions, wherein one or more of the metal foil portions extends laterally beyond the substrate;
• and
• a patterned polyolefin material layer disposed on the conductive contact structure, the patterned polyolefin material layer disposed on and in alignment with the metal foil portions, and the patterned polyolefin material layer coating a top, a bottom and ends of each of the one or more of the metal foil portions that extends laterally beyond the substrate.

A solar cell, comprising:

• a substrate having a back surface and an opposing light-receiving surface;
• a plurality of N-type and P-type semiconductor regions disposed in or above the back surface of the substrate;
• a conductive contact structure disposed over the plurality of N-type and P-type semiconductor regions, the conductive contact structure comprising metal foil portions in alignment with corresponding ones of the N-type and P-type semiconductor regions, wherein one or more of the metal foil portions extends laterally beyond the substrate;
• and
• a patterned wet etchant-resistant polymer layer disposed on the conductive contact structure, the patterned wet etchant-resistant polymer layer disposed on and in alignment with the metal foil portions, and the patterned wet etchant-resistant polymer layer coating a top, a bottom and ends of each of the one or more of the metal foil portions that extends laterally beyond the substrate.