Multijunction solar cell having a lattice mismatched GrIII-GrV-X layer and a composition-graded buffer layer

摘要

A multijunction solar cell includes a first photoactive subcell layer having a first-subcell lattice parameter and a composition including (a) at least one Group III element, at least one Group V element other than (nitrogen, phosphorus), and (nitrogen, phosphorus), or (b) a material selected from the group including GaInAsBi, GaInAsSb, GaInAsP, ZnGeAs₂, or BGaInAs. The multijunction solar cell also has a substrate having a substrate lattice parameter different from the first-subcell lattice parameter, and a composition-graded buffer layer between the first photoactive subcell layer and the substrate and having a buffer-layer lattice parameter graded between the first-subcell lattice parameter and the substrate lattice parameter. The substrate may be a second photoactive subcell layer having a second-subcell lattice parameter different from the first-subcell lattice parameter and sensitive to a second-photoactive-subcell-layer wavelength, and the buffer layer is transparent to the second-photoactive-subcell-layer wavelength.