Infrared Photodetector Features No Dark Current
Researchers at Thales Research and Technology in Orsay, France, and at Université Paris 7 have reported the development of an infrared detector based on the generation of an electronic displacement through a cascade of quantum levels. Called a quantum cascade detector, the device requires no applied bias voltage to operate and therefore displays no dark current. They reported on the detector, which may have applications in small-pixel, large-area focal plane arrays, in the Oct. 4 issue of Applied Physics Letters.
The detector features 40 layers of seven GaAs quantum wells and AlGaAs barriers, sandwiched between Si-doped contact layers. Experiments with a 100 3 100-µm device at 50 K revealed a responsivity of 35 mA/W at a wavelength of 9.2 µm. The integrated quantum efficiency was on the order of a quantum-well infrared photodetector.
- infrared detector
- A device used to detect radiation from the infrared region. It may be a thermal detector, such as a bolometer, thermocouple or Golay cell, or it may be a solid-state photon detector. Infrared-sensitive phosphors may be used in the infrared, and some photographic films may be used in the very near infrared.
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