A photovoltaic (PV) device has at least one lower PV cell on a substrate, the cell having a metallic back contact, and a I-III-VI absorber, and a transparent conductor layer. An upper PV cell is adhered to the lower PV cell, electrically in series to form a stack. The upper PV cell has III-V absorber and junction layers, the cells are adhered by transparent conductive adhesive having filler of conductive nanostructures or low temperature solder. The upper PV cell has no substrate. An embodiment has at least one shape of patterned conductor making contact to both a top of the upper and a back contact of the lower cells to couple them together in series. In an embodiment, a shape of patterned conductor draws current from excess area of the lower cell to the upper cell, in an alternative embodiment shapes of patterned conductor couples I-III-VI cells not underlying upper cells in series strings, a string being in parallel with at least one stack. In an embodiment, the bonding agent is a polymeric adhesive containing conductive nanostructures. In an embodiment the III-V absorber is grown on single crystal, substrate. A method for forming the device is described.