An optoelectronic semiconductor device is disclosed. The device comprises a plurality of stacked p-n junctions (e.g., multi junction device). The optoelectronic semiconductor device includes a n-doped layer disposed below the p-doped layer to form a p-n layer such that electric energy is created when photons are absorbed by the p-n layer. Recesses are formed on top of the p-doped layer at the top of the plurality of stacked p-n junctions. The junctions create an offset and an interface layer is formed on top of the p-doped layer at the top of the plurality stacked p-n junctions. The device also includes a window layer disposed below the plurality stacked p-n junctions. In another aspect, one or more optical filters are inserted into a device to enhance its efficiency through photon recycling. The device can be fabricated by epitaxial growth on a substrate and removed from the substrate through a lift off process.