Mercury-cadmium-telluride thin layers as subterahertz and infrared detectors

摘要

Issues associated with the development and exploitation of infrared (IR) and terahertz (THz) radiation detectors based on a narrow-gap "HgCdTe" semiconductor have been discussed. This mercury-cadmium-tel-luride (MCT) semiconductor can be applied for two-color detector operation in IR and sub-THz spectral ranges. Two-color uncooled and cooled down to 78 K narrow-gap MCT semiconductor thin layers grown using the liquid phase epitaxy or molecular beam epitaxy methods on high-resistive "CdZnTe" or "GaAs" substrates, with bow-type antennas, have been considered both as sub-THz direct detection bolometers and 3 to 10 µm IR photo-conductors. Their room temperature noise equivalent power at the frequency v ≈ 140 GHz and signai-to-noise ratio at the spectral sensitivity maximum under monochromatic (spectral resolution ~0.I μm) globar illumination reached the following values; ~4.5 x 10~(-10) W/Hz~(1/2) and ~50, respectively. Aspheric lenses used for obtaining the images in the sub-THz spectral region were designed and manufactured. With these detectors, about 140 and 270 GHz imaging data have been demonstrated.