Patent ID: 7875906

Claim:
A photodetector, comprising: (a) an InP substrate; (b) an absorption layer that is positioned above the InP substrate and that is one absorption layer selected from the group consisting of: (b1) a Ga 1-x In x N y As 1-y-z Sb z absorption layer, where 0.4≦x≦0.8, 0.0001≦y≦0.12, and 0<z≦0.1; (b2) a Ga 1-x In x N y As 1-y-z P z absorption layer, where 0.4≦x≦0.8, 0.0001≦y≦0.12, and 0.0001≦z≦0.01; and (b3) a Ga 1-x In x N y As 1-y absorption layer, where 0.4≦x≦0.8 and 0.0001≦y≦0.12; (c) a window layer positioned above the absorption layer; and (d) an InGaAs buffer layer positioned between the absorption layer and the window layer, wherein the InP substrate, the absorption layer, the InGaAs buffer layer, and the window layer each have a lattice constant that differs from the lattice constant of any of the other members described above by at most 0.2% of the lattice constant of each of the members being compared.