The fundamental limits of IR detectors are discussed, and the importance of thermal generation rates vis-a-vis photon generation rates is emphasized. The thermal generation rate/area is given by (nt/τ), where n represents the density of relevant carriers (minority or majority), t the device thickness (=α−1, where α is the absorption coefficient), and τ the carrier lifetime. Ultimate IR detector performance is achieved when the photon generation rate/area ηΦB (η is quantum efficiency, ΦB the, incident IR flux density) is greater than (nt/τ).

© 1989 Optical Society of America

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