Metalorganic Chemical Vapor Deposition Grown InAs/GaInSb Strained Layer Superlattices for Infrared Detection

We propose to design and fabricate a two-color detector using InAs/GaInSb strained-layer superlattices (SLS) operating in the 8 to 20 um wavelength region. In the proposed design, superlattices with different periods corresponding to two different wavelengths will be stacked with a thick common layer between them. Among the many advantages of these InAs/GaInSb SLS detectors are excellent uniformity, normal incidence detection, intrinsic absorption, small leakage current, reduced Auger recombination, and compatibility with III-V leakage current, reduced Auger recombination, and compatibility with III-V optotelectronic devices. The unique properties of InAs/GaInSb superlattices will permit both photoconductive and photovoltaic detectors to be constructed. In Phase I, metalorganic chemical vapor deposition (MOCVD) growth conditions for superlattices with different barrier and well thicknesses will be established. Single element photoconductive infrared detectors operating in the 8 to 10 um and 15 to 20 um wavelength regions will be fabricated from the best of these structures. Phase II will optimize barrier thickness, well thickness, and GaInSb composition for absorption at 8 to 20 um, produce and characterize detectors exhibiting this optimal structure, and then assemble these detectors into fully functional arrays.