A photovoltaic assembly dual junction solar cell for space use including a solar cell stack including first and second subcells stacked on each other and each including an epitaxially grown light absorbing layer. The first subcell is adjacent to a solar cell stack front, light-receiving surface and the second subcell is adjacent to a solar cell stack rear surface. The first subcell light absorbing layer has a larger bandgap than the second subcell light absorbing layer. A light reflecting element positioned adjacent to a second subcell light absorbing layer rear side is configured to reflect photons having an energy smaller than the bandgap energy of the second subcell light absorbing layer and/or photons having an energy larger than the bandgap energy of the second subcell light absorbing layer and smaller than the bandgap energy of the first subcell light absorbing layer with a reflectivity of at least 90%.