InSb Photoconductive Detectors in the Far Infrared

Publisher Website
Google Scholar
Abstract
Far infrared detectors using n-type InSb element with lower carrier concentrations are studied to obtain optimum bias current and spectral responsivities as a function of magnetic field. The maximum responsivity of the best detector at 4.2°K is 2600 µV/µW at 190 µm with half width of 40 µm in the magnetic field of 7.32 kOe. The wavelength gibing peak response varies with magnetic field in accordance with cyclotron resonance. Element with low carrier concentration shows desirable characteristics as a narrow band detector. Optimum bias current of the detector is determinable from current-voltage characteristic of the element. Time constant of less than 0.4 µs in rise time and 1.0 µs in decay time is obtained by measuring a cyanide laser pulse. The detector has response even at 2 mm-wavelength and is superior in response and time constant of a Si point contact rectifier.