Normal incidence hole intersubband absorption long wavelength GaAs/Al<i>x</i>Ga1−<i>x</i>As quantum well infrared photodetectors

Abstract

The first long wavelength quantum well infrared photodetector based on valence band intersubband absorption holes is demonstrated. A normal incidence quantum efficiency of η=28% and detectivity of D*λ=3.1×1010 cm √Hz/W at T=77 K, for a cutoff wavelength λc=7.9 μm, have been achieved.