Responsivity of quantum well infrared photodetectors at terahertz detection wavelengths

A first-principles model of the photocurrent in quantum well infrared photodetectors (QWIPs) is derived. The model examines the responsivity, carrier capture probability and quantum efficiency. It is found that the QWIP sensitivity reaches a plateau below the 10 µm detection wavelength and remains nearly constant from 10 to 50 µm. © 2002 American Institute of Physics