NOVELTY - The method comprises depositing a sequence of layers made of semiconductor material on a semiconductor growth substrate (201) to form a solar cell including a subcell composed of a group IV/III-V hybrid alloy. The subcell is composed of germanium deposited between the subcell and the germanium substrate. The sequence of layers includes a first subcell having a band gap of 0.91-0.95 eV, and a second subcell having a band gap of 1.13-1.24 eV. The step of depositing the sequence of layers includes forming the first solar subcell on the substrate having a first band gap.    USE - The method is useful for manufacturing a solar cell, which is useful in satellite and other space related applications.    ADVANTAGE - The method is capable of effectively manufacturing a solar cell with light weight and high energy conversion efficiency, and reduces the interface recombination loss and improves the photogenerated current densities.    DETAILED DESCRIPTION - The method comprises depositing a sequence of layers made of semiconductor material on a semiconductor growth substrate (201) to form a solar cell including a subcell composed of a group IV/III-V hybrid alloy. The subcell is composed of germanium deposited between the subcell and the germanium substrate. The sequence of layers includes a first subcell having a band gap of 0.91-0.95 eV, and a second subcell having a band gap of 1.13-1.24 eV. The step of depositing the sequence of layers includes forming the first solar subcell on the substrate having a first band gap, forming the second solar subcell over the first subcell having a second band gap smaller than the first band gap, forming a third solar subcell over the second solar subcell having a third band gap smaller than the second band gap, forming a fourth solar subcell having a fourth band gap smaller than the third band gap that is lattice matched to the third solar subcell, and forming a fifth solar subcell over the fourth solar subcell having a fifth band gap smaller than the fourth band gap. Some of the layers are deposited with metal organic chemical vapor deposition processes at 300 degrees C. The coefficient of thermal expansion between the growth substrate and the layers of semiconductor material are matched to avoid cracking. The method further comprises forming a tunnel diode composed of germanium silicon tin between the first subcell composed of germanium and the second subcell composed of germanium silicon tin, depositing a layer a back surface field layer (204) composed of germanium silicon tin over the growth substrate, depositing germanium buffer layer over the germanium growth substrate, and forming a window layer adjacent to the subcell. The germanium subcell has a band gap of 0.73 eV. A junction is formed in the group IV/III-V hybrid alloy to form a photovoltaic subcell by the diffusion of arsenic and/or phosphorus into the hybrid alloy layer.    DESCRIPTION OF DRAWING(S) - The figure shows a cross-sectional view of the solar cell.    Substrate (201)    Nucleation layer (202)    Buffer layer (203)    Back surface field layer (204)    P-base layer. (105)