A 10 MU-M GAAS ALXGA1-XAS INTERSUBBAND PHOTODETECTOR OPERATING AT ZERO-BIAS VOLTAGE/

We report on a GaAs/AlxGa1-xAs quantum well intersubband photodetector for the long wavelength infrared region, which operates at zero bias voltage. Detection without bias is achieved by using an asymmetrical b arrier structure as well as modulation doping, giving rise to a built- in field across the barrier layers. The maximum of the spectral respon se is centered at 10 mu m with a spectral bandwidth of 1.6 mu m and a 77 K peak detectivity of 2.5x10(9) cm root Hz/W at 0 V. (C) 1996 Ameri can Institute of Physics.