Tuesday, March 28, 2023, 4:00pm-5:00pm GN230
Molecular beam epitaxy and device performance in group III-V semiconductors for space-based sensing
With new advances in rocket technologies, object launches into space have been seeing an exponential rate of increase over the past decade. This is driving a paradigm shift in onboard satellite technologies towards more low-cost implementations with higher yields and manufacturability, which impacts performance and rad-tolerance requirements. Group III-V-based mid-wavelength infrared materials have shown promise to deliver a scalable infrared technology for satellite-based sensing. Here, the molecular beam epitaxy growth and characterization of mid-wavelength infrared III-V InAs/InAsSb and InGaAs/InAsSb type‑II superlattices and quinary GaInAsSbBi materials are explored. The superlattices’ temperature dependent bandgap and minority carrier lifetime are extracted and used to develop a physics-based model of device dark current and quantum efficiency as a function of temperature and proton irradiation to simulate device degradation in a space radiation environment. Results show that an absorber doping grade reduces the dark current and inverse quantum efficiency degradation rate and is attributed to an effective mobility enhancement and high unirradiated quantum efficiency. Then, a quinary GaInAsSbBi is grown by molecular beam epitaxy and shows a minority carrier lifetime improvement due to the incorporation of Bi in comparison to a calibration quaternary GaInAsSb. This result is attributed to the surfactant behavior of Bi when it's introduced during growth. The quinary bandgap exhibits a 4.4 µm cutoff, a 0.5 µm extension beyond lattice matched InAsSb and is similar to a quaternary InAsSbBi previously grown at 360 oC. These incremental improvements in material quality provide a path forward for new material designs to continue enhancing overall detector performance, and eventually realize an industry-ready detector architecture
