A twohyphen;color infrared detector using GaAs/AlGaAs and strained InGaAs/AlGaAs multiquantum wells is demonstrated. The response peak of the GaAs/AlGaAs quantum well is at 8 mgr;m, and that of the InGaAs/AlGaAs quantum well is at 5.3 mgr;m. The responsivity of the detector is 1 A/W at 8 mgr;m and 0.27 A/W at 5.3 mgr;m; these are the best values reported for a twohyphen;color quantum well infrared detectors (QWIPs) with peak sensitivities in the spectral regions of 3ndash;5.3 mgr;m and 7.5ndash;14 mgr;m. Singlehyphen;colored 5.3 and 8 mgr;m QWIPs were also fabricated to study the bias dependent behavior. This behavior can be explained using the concept of current continuity. Because of a higher electrical resistance, a high electric field domain is always formed first in the shorter wavelength quantum well stack.
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