Ge-Si/Si infra-red, zone-folded superlattice detectors

Superlattice photovoltaic waveguide detectors have been fabricated and tested with a strained-layer superlattice active region of four alternating atomic monolayers of Ge and Si. The infra-red spectral response extends to 1.4 μm. The peak of the optical response is shifted toward the visible relative to Ge-Si alloy detectors of a similar average composition.