Abstract: An integrated, monolithic array of solar cells wherein isolation between cells permits series interconnection of the cells to provide an output voltage for the array equal to the sum of the voltages of the unit cells. Although normal PN junction isolation is ineffective when exposed to light, the present structure includes a form of junction isolation that is effective when exposed to light, or to other radiation. For example, a band of heavily doped P-type silicon, formed by thermomigration of aluminum through an N-type wafer, provides such isolation.

Abstract: A solar cell having first and second closely spaced, parallel P-N junctions is fabricated, wherein the illuminated surface is totally free of metallization, i.e., the junction nearest the illuminated surface is not electrically connected, and thereby participates only indirectly in the collection of photo-generated carriers by providing a charge field to suppress the front surface recombination and to enhance collection at the back side junction. All metallization is on the back side, which preferably includes an interposed finger pattern of N+ and P+ zones.