Indium aluminium antimonide (In1-xAlxSb) and cadmium mercury telluride
(CdxHg1-xTe) heterostructure diodes, which comprise a near intrinsic a
ctive region bounded by more highly doped contact regions, exhibit pos
itive or negative luminescence at medium to long infrared wavelengths
when forward or reverse biased respectively at room temperature. In re
verse bias, the carrier densities in the near intrinsic region are red
uced below their equilibrium values by the effects of exclusion and ex
traction. In consequence, the radiative recombination is reduced and t
he devices emit less infrared radiation than the thermal equilibrium v
alue. The observed intensity of the negative luminescence is in genera
l agreement with expected values.