| Abstract: | A photodetector is disclosed for the detection of infrared light with a
long cutoff wavelength in the range of about 4.5-10 microns. The
photodetector, which can be formed on a semiconductor substrate as an nBn
device, has a light absorbing region which includes InAsSb
light-absorbing layers and tensile-strained layers interspersed between
the InAsSb light-absorbing layers. The tensile-strained layers can be
formed from GaAs, InAs, InGaAs or a combination of these III-V compound
semiconductor materials. A barrier layer in the photodetector can be
formed from AlAsSb or AlGaAsSb; and a contact layer in the photodetector
can be formed from InAs, GaSb or InAsSb. The photodetector is useful as
an individual device, or to form a focal plane array. |