Solar cell stack comprising III-V semiconductor layers, which includes a first subcell having a first band gap and a first lattice constant and which includes a second subcell having a second band gap and a second lattice constant, and which includes an intermediate layer sequence disposed between the two solar cells. The intermediate layer sequence including a first barrier layer and a first tunnel diode and a second barrier layer, and the layers being arranged in the specified order. The tunnel diode includes a degenerate n+ layer having a third lattice constant and a degenerate p+ layer having a fourth lattice constant, the fourth lattice constant being smaller than the third lattice constant, and the first band gap being smaller than the second band gap, and the p+ layer having a different material composition than the n+ layer.