Optical and transport properties of single quantum well infrared photodetectors

We have performed an extensive series of measurements on symmetrical barrier bound-to-continuum and asymmetrical barrier bound-to-bound quantum well infrared photodetectors consisting of only a single well. We find that the behavior of the optical (e.g., responsivity) and transport properties (e.g., gain) as a function of bias is strikingly different from that of the usual multi-quantum well detectors. The simplicity of the structure has allowed an accurate theoretical calculation of the potential drops across each barrier, the photoinduced carrier depletion in the quantum well and therefore a detailed understanding of the device physics.