NOVELTY - Forming solar-cell array (100) with integrated bypass diodes, comprises e.g.: providing structure comprising semiconductor substrate (110), a first cell containing e.g. silicon germanium p-n junction, and at least one second cell each containing e.g. III-V-semiconductor p-n junction; forming over a top surface of substrate, a many discrete solar cells; forming a bypass diode that is discrete and laterally separate from its associated solar cell and comprises unremoved portion of first cell; and electrically connecting each bypass diode with its associated discrete solar cell.    USE - The method is useful for forming a solar-cell array with integrated bypass diodes.    ADVANTAGE - The method fabricates high-efficiency solar-cell arrays.    DETAILED DESCRIPTION - Forming a solar-cell array (100) with integrated bypass diodes, comprises: providing a structure comprising a semiconductor substrate (110), disposed over the substrate, a first cell comprising a silicon germanium p-n junction or silicon germanium p-intrinsic-n junction, and disposed over the first cell, at least one second cell each comprising III-V-semiconductor p-n junction or III-V-semiconductor p-intrinsic-n junction; forming over a top surface of the substrate a many discrete solar cells at least in part by removing portions of the first cell and the second cells to form the discrete solar cells and regions between them that do not produce electrical current under solar illumination, where each of the discrete solar cells are a multi junction solar cell incorporating, in series, an unremoved portion of the first cell and an unremoved portion of the second cells; forming, associated with each of the discrete solar cells, a bypass diode that is discrete and laterally separate from its associated solar cell and comprises an unremoved portion of the first cell, where the formation comprises removing an unremoved portion of the second cells; electrically connecting each bypass diode with its associated discrete solar cell such that the bypass diode and the discrete solar cell have opposite polarities; and electrically connecting, on the substrate, many of the discrete solar cells in series, thus forming 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.    DESCRIPTION OF DRAWING(S) - The figure shows cross-sectional view o fvarious steps for the formation of solar cell arrays with integrated devices.    Solar-cell array (100)    Substrate (110)    Graded composition layer (126)    Isolation diode (128)    Cap layer (150)