19 μm cutoff long-wavelength GaAs/AlxGa1−xAs quantum-well infrared photodetectors

Abstract
The longest‐wavelength quantum‐well infrared photodetector ever achieved, with a cutoff wavelength λc=19 μm, is demonstrated. Detailed measurements and an in‐depth analysis of the noise, optical gain, detectivity, quantum efficiency, and quantum‐well escape probability, are also discussed.