ABSTRACT
In the middle and late 1950s it was discovered that InSb had the smallest energy gap of any semiconductor known at that time and its applications as a middle wavelength infrared (MWIR) detector became obvious [1,2]. The energy gap of InSb is less well matched to the 3–5 μm band at higher operating temperatures, and better performance can be obtained from Hg1− xCdxTe. InAs is a similar compound to InSb but has a larger energy gap [3], so that the threshold wavelength is 3–4 μm, and both photoconductive and photovoltaic detectors have been fabricated. The photoconductive process in InSb has been studied extensively, and more details can be found in Morten and King [4], Kruse [5], and Elliott and Gordon [6].
