Broadband 8–12 μm high-sensitivity GaAs quantum well infrared photodetector

Broadband GaAs/AlxGa1−xAs quantum well infrared detectors grown by molecular beam epitaxy have been demonstrated which are sensitive over the λ=8–12 μm atmospheric window spectral region. These are the first high-detectivity bound state to extended state quantum well detectors which are peaked at λ=10 μm. The spectral bandwidth (Δν/ν) of these devices is three times larger than our earlier λ=8 μm device. The detectivity D* is background limited at T=50 K with D*=1×1010 cm (Hz)1/2 /W, and a noise equivalent temperature change of NEΔT=0.01 K.