Mechanically stacked tandem photovoltaic cells with intermediate optical filters

A multi-junction photosensitive device comprising:

• a first subcell disposed on a reflective substrate, wherein the first subcell comprises at least a first photoactive layer situated on a first transparent contact wherein the first transparent contact is precoated with a noble metal;
• a second subcell disposed on a transparent substrate, wherein the second subcell comprises at least a second photoactive layer situated on a second transparent contact wherein the second transparent contact is precoated with a noble metal, wherein the first and second subcells are located between the reflective substrate and the transparent substrate in a stacked configuration, and wherein the first and second subcells are cold-weld bonded to one another by a metal grid that physically and electrically interconnects the subcells by applying pressure on each of the first transparent contact and the second transparent contact, and
• at least one optical filter layer located between the first and second subcells,
• wherein the first photoactive layer comprises PbS quantum dots and the second photoactive layer comprises an organic photovoltaic,
• wherein the first and second photoactive layers absorb different wavelengths of light.