In this communication, we report results obtained on a new InSb/InAlSb/InSb ‘bariode’, grown by MBE on (100)-
oriented InSb substrate. Because of a very weak valence band offset with InSb (~ 25meV), InAlSb is a good candidate as
a barrier layer for electrons. However, due to lattice mismatch with the InSb substrate, careful growth study of InAlSb
was made to insure high crystal quality. As a result, InSb-based nBn detector device exhibits dark current density equals
to 1x10-9A.cm-2 at 77K: two decades lower than Insb standard pin photodiode with similar cut-off wavelength.
Moreover, compared to standard pn (or pin) InSb-based photodetectors fabricated by implanted planar process or by
molecular beam epitaxy (MBE), we demonstrate that the reachable working temperature, around 120 K, of the InSbbased
nBn detector is respectively higher than 40 K and 20 K than the previous. Such result demonstrates the potentiality
of Insb detectors with nBn architecture to reach the high operating temperature.
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