Mm- and THz-waves detector on the base of narrow-gap semiconductors

Narrow-gap direct detection mercury cadmium telluride (MCT) THz semiconductor hot electron bolometer (SHEB) is considered. Device operation takes into account the phenomena in semiconductor bipolar plasma and hot-carrier effect at uncooled or slightly cooled conditions. To examine the SHEB detector in the wide range of operation frequencies (ν=0.037-1.58 THz) the simplest dipole antennas were used in prototype arrays. The experiments were performed at T = 300 K at ν= 37, 50, 75 GHz, 0.89 and 1.58 THz with a MCT SHEB devices with intrinsic conductivity. At ν=1.58, 0.89, 0.078 and 0.037 THz the signal temperature dependencies were measured too. The sensitivity was S v ~2.5 V/W (estimated NEP~4×10 -10 W/Hz 1/2 ) at T =300 K; and S v ~2×10 3 V/W (estimated NEP~3×10 -12 W/Hz 1/2 ) at T =78K and ν=37, and 78 GHz. The signal temperature dependences at ν=0.89 THz are different compared to those at ν=37 and 78 GHz. Temperature phase dependent signals are discussed with their dependence on energy relaxation time. A model of such a detector is developed. The radiation entrance through semiconductor surface and metal contacts are both modeled.