High-efficiency solar-cell arrays with integrated devices and methods for forming them

A solar-cell array with integrated bypass diodes, the array comprising:

• a substrate;
• disposed over the substrate, a plurality of discrete solar cells electrically connected in series to form a series string of discrete solar cells for supplying, under solar illumination, a voltage larger than a voltage produced by any of the discrete solar cells individually, each of the discrete solar cells comprising (i) a first cell comprising a SiGe p-n junction, a SiGe p-i-n junction, a III-V-semiconductor p-n junction, or a III-V-semiconductor p-i-n junction, and (ii) disposed over the first cell, one or more second cells each comprising a III-V-semiconductor p-n junction or a III-V-semiconductor p-i-n junction;
• and
• disposed over the substrate, a plurality of bypass diodes, each bypass diode (i) being associated with a different discrete solar cell, (ii) being discrete and laterally separate from its associated solar cell, and (iii) comprising at least a portion of the first cell without the one or more second cells thereover, a distance between the substrate and the at least a portion of the first cell of the bypass diode being approximately equal to a distance between the substrate and the first cell of the solar cell associated with the bypass diode,
• wherein each bypass diode is electrically connected with its associated solar cell such that the bypass diode and the discrete solar cell have opposite polarities.