Indium Antimonide detectors

Paul W. Kruse, Indium Antimonide Photoconductive and Photoelectromagnetic Detectors... 

While most other techniques use a limited amount of detectors (e.g., silica for visible, photomultipliers for UV) and MIR has a small number, NIR uses many types of semiconductors for detectors. The original PbS detectors are still one of the largest used in NIR, however, indium gallium arsenide (InGaAs), indium arsenide (InAs), indium antimonide (InSb), and lead selenide (PbSe) are among the semiconductor combinations used, both cooled and ambient. 

Indium antimonide is used in semiconductor and Hall effect devices, and infrared detectors. 

From the exit slit, the beam is directed to either of two detectors by the movable mirror behind the exit slit. Typical detectors are InSb, a photovoltaic indium antimonide detector operated at 77 K, and He Ge, a photo-conductive mercury-doped germanium detector maintained at 15 K by a closed-cycle helium refrigerator... 

Typical materials used in NIR photoconductive detectors are PbS, PbSe, InSb and InAs (lead sulphide, lead selenide, indium antimonide and indium arsenide). 

Arrivo SM, Kleiman VD, Dougherty TP, Heilweil EJ. Broadband femtosecond transient infrared spectroscopy using a 256 x 256 element indium antimonide focal-plane detector. Optics Lett 1997 22(19) 1488-1490. 

This type of detector is constituted, for the mid-IR region, of a ternary alloy of mercury-cadmium telluride (MCT) or indium antimonide (InSb) deposited upon an inert support and for the near-IR of lead sulfide (PbS) or an other ternary alloy of indium/gallium/arsenic (InGaAs). Sensitivity is improved when these detectors are cooled down to liquid nitrogen temperature of (77 K). 

Photon detectors consist of a thin film of semiconductor material, such as lead sulfide, lead telluride, indium antimonide, or germanium doped with copper or mercury, deposited on a nonconducting glass and sealed into an evacuated envelope. Photon flux impinging on the semiconductor increases its conductivity. Lead-sulfide detectors are sensitive to radiation below about 3 fj.m in wavelength and have a response time of about 10 /nsec. Doped germanium detectors cooled to liquid-helium temperatures are sensitive to radiation up to about 120 jitm in wavelength, and have a response time of approximately 1 nsec. 

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