Stack-shaped multiple solar cell (MS) for increasing radiation stability, comprising a first part cell (SC1), wherein the first part cell predominantly comprises germanium with a germanium component above 95%, and a second part cell (SC2), wherein the second part cell (SC2) has a greater band gap than the first part cell (SC1), and each of the part cells (SC1, SC2) has an emitter and a base, - wherein the second part cell (SC2) comprises a GaInAsP layer and the thickness of the GaInAsP layer is greater than 100 nm and the GaInAsP layer is formed as part of the emitter and/or as part of the base and the phosphorus content of the GaInAsP layer is smaller than 65% or larger than 80%, and - a third part cell (SC3) is provided and the third part cell (SC3) contains a layer consisting of a compound of GaInP and/or AlGaInP and the thickness of the GaInP layer or the AlGaInP layer is larger than 100 nm and the GaInP layer or the AlGaInP layer is formed as part of the emitter and/or as part of the base, and - a metamorphic buffer (MP1) is formed between the first part cell (SC1) and the second part cell (SC2), wherein the metamorphic buffer (MP1) comprises a sequence of at least three layers and the lattice constant in the case of the sequence in the direction of the second part cell (SC2) increases from layer to layer, and - no direct semiconductor bond is formed between any two part cells and the indium content of the GaInAsP layer is smaller than 50%. a first part cell (SC1), wherein the first part cell predominantly comprises germanium with a germanium component above 95%, and a second part cell (SC2), wherein the second part cell (SC2) has a greater band gap than the first part cell (SC1), and each of the part cells (SC1, SC2) has an emitter and a base, - wherein the second part cell (SC2) comprises a GaInAsP layer and the thickness of the GaInAsP layer is greater than 100 nm and the GaInAsP layer is formed as part of the emitter and/or as part of the base and the phosphorus content of the GaInAsP layer is smaller than 65% or larger than 80%, and - a third part cell (SC3) is provided and the third part cell (SC3) contains a layer consisting of a compound of GaInP and/or AlGaInP and the thickness of the GaInP layer or the AlGaInP layer is larger than 100 nm and the GaInP layer or the AlGaInP layer is formed as part of the emitter and/or as part of the base, and - a metamorphic buffer (MP1) is formed between the first part cell (SC1) and the second part cell (SC2), wherein the metamorphic buffer (MP1) comprises a sequence of at least three layers and the lattice constant in the case of the sequence in the direction of the second part cell (SC2) increases from layer to layer, and - no direct semiconductor bond is formed between any two part cells and - wherein the second part cell (SC2) comprises a GaInAsP layer and the thickness of the GaInAsP layer is greater than 100 nm and the GaInAsP layer is formed as part of the emitter and/or as part of the base and the phosphorus content of the GaInAsP layer is smaller than 65% or larger than 80%, and - a third part cell (SC3) is provided and the third part cell (SC3) contains a layer consisting of a compound of GaInP and/or AlGaInP and the thickness of the GaInP layer or the AlGaInP layer is larger than 100 nm and the GaInP layer or the AlGaInP layer is formed as part of the emitter and/or as part of the base, and - a metamorphic buffer (MP1) is formed between the first part cell (SC1) and the second part cell (SC2), wherein the metamorphic buffer (MP1) comprises a sequence of at least three layers and the lattice constant in the case of the sequence in the direction of the second part cell (SC2) increases from layer to layer, and - no direct semiconductor bond is formed between any two part cells and the indium content of the GaInAsP layer is smaller than 50%. <EOS>