The wavelength of the responsive peak resulted from electron interferences for multi-quantum well infrared detectors

The wavelength of the responsive peak for GaAs/Al0.3Ga0.7As multi-quantum well (MQW) infrared detectors was measured to be λ=6.29μm at 77K. Based on the theory of electron interference, the results calculated for the MQW structure indicate that there may be a series of separated conduction states above the barriers, on which the electrons can propagate along the direction perpendicular to well/barrier interfaces. For the quantum well parameters given in this article, the wavelength of light absorbed is calculated to be 6.29μm when optical excitations occur for which electrons transit from Fermi level in quantum wells to the first conduction state E1 above the barriers. The theoretical value for the responsive peak wavelength is in very good agreement with the measurement result. This shows that the wavelength of the responsive peak resulted from electron interferences for the MQW infrared detectors.