Design for electronic spectrally tunable infrared detector

A single element infrared detector consisting of multiple layers of successive epilayers of lead chalcogenides or their alloys with tin or cadmium to form two or more adjacent contiguous surfaces whereupon each surface is deposited with an ohmic contact. The multiple adjacent semiconductor surfaces are also each fitted or equipped with an non-ohmic contact that yields novel applications in terms of broad band and narrow scanning, particular when the epilayers are geometrically arranged to selectively allow the transmission of radiation to yield both broad band and narrow band responses concurrently so as to obtain a separate electrical signal from each adjacent contiguous semiconducting epilayer surface.