Patent ID: 8772623

Claim:
A monolithic, multi-bandgap, photovoltaic converter, comprising: a first subcell comprising GaInAs(P) with a first bandgap and a first lattice constant; a second subcell comprising GaInAs(P) with a second bandgap and a second lattice constant, wherein the second bandgap is less than the first bandgap and the second lattice constant is greater than the first lattice constant, and further, wherein the second lattice constant is equal to a lattice constant of a InAs y P 1-y alloy with a bandgap greater than the first bandgap; and a lattice constant transition material positioned between the first subcell and the second subcell, said lattice constant transition material comprising InAs y P 1-y alloy with a lattice constant that changes gradually from the first lattice constant to the second lattice constant.