NOVELTY - An assembly for a photovoltaic cell comprises: a set of subcells configured in a stack, the set of subcells comprising a top subcell having an outward-facing surface; an electrically conductive interconnect layer disposed between at least two of the subcells in the set of subcells; and at least one via between the interconnect layer and the outward-facing surface of the top subcell, where the interconnect layer permits an electrical connection between at least one subcell and the via.    USE - The assembly is useful for a photovoltaic cell, preferably a multi-junction photovoltaic cell; also the method is useful for compensating for loss of current in a multi-junction photovoltaic cell (all claimed). The multi-junction photovoltaic cell is also useful for converting solar energy into electrical energy.    ADVANTAGE - The assembly can improve cell efficiency over variable lighting conditions, and improves the multi-junction photovoltaic cell's total output current.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are:    (1) a multi-junction photovoltaic cell comprising: the set of subcells comprising a front subcell having an outward-facing surface, a back subcell, and one or more middle subcells, where the one or more middle subcells are configured in a stack between the front subcell and the back subcell; an output terminal in communication with the front subcell and an output terminal in communication with the back subcell, where the output terminals are configured to receive an electrical load; and an interconnect layer disposed between each of the subcells in the set of subcells; for each of the interconnect layers, a set of vias configured to provide electrical communication between the outward-facing surface of the front subcell and the interconnect layer, and a conductive connector contacting the set of vias and configured to provide electrical communication between the interconnect layer and a microprocessor configured to measure the current or voltage from the interconnect layer; and    (2) a method of compensating for loss of current in a multi-junction photovoltaic cell comprising the set of subcells, comprising: sequentially evaluating a current or voltage for each subcell in the set of subcells, where evaluating comprises: electrically bypassing all but one of the subcells in the set of subcells, measuring the current or voltage generated by the subcell that is not bypassed, and determining whether the current or voltage generated by the subcell that is not bypassed is below a threshold value; and electrically bypassing one or more subcells in the set of subcells that were evaluated as generating a current or voltage below the threshold value.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic top-down representation of the multi-junction photovoltaic cell.    Light-facing surface (101)    Top subcell (113)    First via (117)    Second via (119)    Front contact (129)    Conductive connectors (301, 303)