Design for new structure InAs/InxGa1−xSb superlattice two-color—short and long wavelength infrared photodetector

InAs/InxGa1−xSb superlattices have been used in short and long wavelength infrared photodetectors, respectively, as detective material with advanced molecular beam epitaxy (MBE) technology, but this two wave bands simultaneous detection at the same photodetector using the same detection material has rarely been realized. GaAs-based two-color infrared detection arrays using double detector structure that needs more complex photolithography and epitaxial processing than one color device have been presented. Nevertheless, in that case, the fulfillment of two wave band detection is actually by two type of geometrically designed materials of the same detector, which is essentially equivalent to two type of detectors on the array wafer. In this paper, we design a new structure InAs/InxGa1−xSb superlattice two-color (short and long wavelength infrared) photodetector, in which special doping and layer structure and double external electrocircuits have been utilized to separate and detect photocurrents of the two infrared spectra. Furthermore, the two-color infrared simultaneous detection is fulfilled on the same detective material.