Three-color broadband asymmetric quantum well infrared photodetectors in long wavelength infrared range (LWIR)

A theoretical investigation of a GaAs/AlGaAs-material-system-based four quantum well infrared detector structures consisting of ten periods of three asymmetric quantum well units are presented. Each quantum well in the units is sensitive to wavelengths of 8.75, 10, and 11.75 mu m, respectively. The effect of the barrier thicknesses on the responsivity spectra is discussed with respect to barrier transmissions under negative and positive bias voltages. Each detector structure shows voltage-tunable broadband and multicolor features in 8-12-mu m long wavelength infrared range (LWIR).