Long-wavelength GaAs quantum-well infrared photodetectors

GaAs quantum-well IR photodetectors (QWIPs) that operate at a range of peak absorption wavelengths are considered in terms of their characteristics and potential applications. The structures of some QWIPs are described with references to their band diagrams, absorption coefficients, low-temperature quantum efficiencies, and peak detectivities. Peak detectivity is shown to be temperature- and bias-dependent and to be linked to doping density, and the QWIP technology in general has high peak detectivities and good uniformity for the production of large-area 2D arrays.