Patent ID: 8093559

Claim:
A device for infrared radiation detection, said device comprising: (a) a first absorber layer having a first conductivity type and a first band gap, wherein said first absorber layer consists substantially of a first semiconductor composition selected from the group consisting of InP, InAlAs, AlGaAsSb, AlInAsSb, and combinations thereof, wherein the stoichiometry of said first semiconductor composition provides a first semiconductor lattice constant that is within one-half of one percent of the lattice constant of InP; (b) a second absorber layer having a second conductivity type and a second band gap, wherein said first band gap is greater than said second band gap, and wherein said second absorber layer consists substantially of a second semiconductor composition selected from the group consisting of InGaAlAs, InGaAsP, and combinations thereof, wherein the stoichiometry of said second semiconductor composition provides a second semiconductor lattice constant that is within one-half of one percent of the lattice constant of InP; (c) a first barrier layer that separates said first absorber layer from said second absorber layer; (d) a third absorber layer having said first conductivity type and a third band gap, wherein said second band gap is greater than said third band gap, and wherein said third absorber layer consists substantially of a third semiconductor composition that includes at least two elements selected from a first group consisting of In, Ga, and Al and further includes at least one element selected from a second group consisting of As, P, N, and Sb, wherein the stoichiometry of said third semiconductor composition provides a third semiconductor lattice constant that is within one-half of one percent of the lattice constant of InP; (e) a second barrier layer that separates said second absorber layer from said third absorber layer; (f) a two-terminal mesa or planar detector architecture with suitable electrical connections and contact layers to said first and third absorber layers, effective for facilitating application of a bias voltage for tuning a wavelength response; and (g) a read-out integrated circuit to detect current generated.