Design of an achievable, all lattice-matched multijunction solar cell using InGaAlAsSb

A design for a realistically achievable, multijunction solar cell based on all lattice-matched materials with >50% projected efficiencies under concentration is presented. Using quaternary materials such as InAlAsSb and InGaAlAs at stochiometries lattice-matched to InP substrates, direct bandgaps ranging from 0.74eV up to ∼1.8eV, ideal for solar energy conversion, can be achieved. In addition, multi-quantum well structures are used to reduce the band-gap further to <0.7 eV. A triple-junction (3J) solar cell using these materials is described, and in-depth modeling results are presented showing realistically achievable efficiencies of AM1.5D 500X of η ∼ 53% and AM0 1 Sun of η∼ 37%.