Development of Ultra-Low Noise, High Sensitivity Planar Metal Grating Coupled III-V Multiquantum Well Infrared Detectors for Focal Plane Array Staring IR Sensor Systems

摘要

During this reporting period we have continued to make progress towards theprogram goals. We have designed, fabricated, and characterized several new types of 2-D metal grating coupled n-type GaAs/AlGaAs, AlAS/AlGaAs,InAlAs/InGaAs, and InGaP/GaAs QWIPs for 2-14 micrometers focal plane arrays (FPAs) staring infrared sensor applications. In addition, a new normal incidence two-color p-type strained layer InGaAs/InA1As QWIP has been developed for the first time with highest detectivity and low dark current reported for a p-type QWIP. Specific tasks performed during this period include: (1) design, growth, and fabrication of a new normal incidence p-type strained InGaAs/InA1As QWIP grown on InP substrate by MBE technique, (2) completed theoretical and experimental studies of four dual mod operation QWIPs fabricated from n-type GaAs/AlGaAs, InGaAs/InAlAs, and AlAs/AiGaAs material systems, (3) completed theoretical and experimental studies of a type-II AlAs/AlGaAs QWIP, (4) developed a new 2-D square mesh metal grating coupled structure for an InAlAs/InGaAs BTM QWIP with significant improvement in detector's responsivity and detectivity, (5) performed noise characterization on the InGaAs/InAlAs QWIP and identified the noise sources in this QWIP, (6) completed numerical simulations of coupling quantum efficiency versus grating periodicity and grating dimension for a 2-D square mesh metal grating coupler formed on both the standard and BTM QWIPs.