High performance InGaAs/GaAs quantum well infrared photodetectors

We have measured the optical and transport properties of In0.2Ga0.8As/GaAs quantum well infrared photodetectors based on bound-to-bound, bound-to-quasibound, and bound-to-continuum intersubband transitions. Excellent hot electron transport and high detectivity D*=1.8×1010 cm√Hz/W (at λp=16.7 μm) were achieved at temperature T=40 K.