| Abstract: | A photodetector for detecting infrared light in a wavelength range of
3-25 .mu.m is disclosed. The photodetector has a mesa structure formed
from semiconductor layers which include a type-II superlattice formed of
alternating layers of InAs and In.sub.xGa.sub.1-xSb with
0.ltoreq.x.ltoreq.0.5. Impurity doped regions are formed on sidewalls of
the mesa structure to provide for a lateral conduction of photo-generated
carriers which can provide an increased carrier mobility and a reduced
surface recombination. An optional bias electrode can be used in the
photodetector to control and vary a cut-off wavelength or a depletion
width therein. The photodetector can be formed as a single-color or
multi-color device, and can also be used to form a focal plane array
which is compatible with conventional read-out integrated circuits. |