Space vehicles including multijunction metamorphic solar cells

A method of manufacturing a plurality of space vehicles for use in a satellite constellation, comprising;

• providing a plurality of space vehicles, each space vehicle including housing having a first side and opposite side, and axis;
• a first elongated rectangular sheet including an array of transducer devices including multijunction solar cells mounted on, and extending from a surface of the first side of the housing and a second elongated, rectangular sheet including an array of transducer devices including multijunction solar cells mounted on, and extending from a surface of the second side of the housing:
• wherein each of the multijunction solar cells are fabricated by the steps of:
• providing a germanium growth substrate;
• forming a first or bottom solar subcell disposed over or in the germanium growth substrate;
• forming a graded interlayer over the germanium growth substrate;
• providing a first middle solar subcell disposed over the graded interlayer and lattice mismatched with respect to the growth substrate having the selected band gap in the range of 1.06 to 1.41 eV;
• providing an upper solar subcell disposed over the first middle solar subcell and having the selected band gap in the range of 1.95 to 2.20 eV;
• and lattice mismatch with respect to the growth substrate;
• wherein the graded interlayer is compositionally graded to lattice match the growth substrate on one side and the first middle solar subcell on the other side, and is composed of the As, P, N, Sb based III-V compound semiconductors subject to the constraints of having the in-plane lattice parameter throughout its thickness being greater than or equal to that of the growth substrate.

A method of manufacturing a multijunction solar cell for use in a space vehicle comprising:

• providing a germanium growth substrate;
• forming a first solar subcell over or in the growth substrate;
• growing a graded interlayer over the growth substrate, followed by a sequence of layers of semiconductor material using a deposition process to form a solar cell comprising a plurality of subcells including:
• a first middle solar subcell disposed over and lattice mismatched with respect to the growth substrate and having a band gap in the range of 1.06 to 1.41 eV;
• a second middle solar subcell disposed over the first middle solar subcell and having a band gap in the range of approximately 1.35 to 1.66 eV;
• a third middle solar subcell disposed over and lattice mismatched with respect to the growth substrate and having a band gap in the range of 1.665 to 1.95 eV;
• and
• an upper solar subcell disposed over the last middle solar subcell and having an aluminum content in excess of 30% by mole fraction, and having a band gap in the range of 1.95 to 2.20 eV;
• wherein the graded interlayer is compositionally graded to lattice match the growth substrate on one side and the first middle solar subcell on the other side, and is composed of the As, P, N, Sb based III-V compound semiconductors subject to the constraints of having the in-plane lattice parameter throughout its thickness being greater than or equal to that of the growth substrate.