Defense Technical Information Center Compilation Part Notice ADP 015106 TITLE : AlGaAsSb-InGaAsSb-GaSb Epitaxial Hetero structures for Uncooled Infrared Detectors
To order the complete compilation report, use: ADA423729 The component part is provided here to allow users access to individually authored sections f proceedings, annals, symposia, etc. However, the component should be considered within [he context of the overall compilation report and not as a stand-alone technical report. Abstract Lattice matched n-type AlGaAsSb-InGaAsSb-GaSb heterostructures for uncooled infrared detectors including separate absorption and multiplication avalanche photodiodes (SAM-APD) as well as low-voltage InGaAsSb APDs were grown using inexpensive liquid phase epitaxy. Formation of the pn-junction was performed through diffusion of Zn from the vapor phase. Responsivity at X = 2 pm as high as 3.5 A/W was achieved in InGaAsSb APD biased at 8 V with the avalanche multiplication starting at 6 V. Our calculations have shown that the above parameters can result in a NEP value as low as lxl0-2 W or D* value as high as 2x10 10 cm'Hz 1 1 2 /W at room temperature for 400 gim diameter (200 pm diameter photoactive area) APD diodes.
InGaAsSb photovoltaic cells with enhanced open-circuit voltage
Various Zn diffusion profiles in InGaAsSb photovoltaic cells with diffused emitters were experimentally studied. It was determined that strong built-in electric fields near the surface lead to a reduction of the saturation value of the injection (J/sub 01/) component of the dark current, and hence to the increase of the open-circuit voltage (V/sub oc/). A value of J/sub 01/ as low as 4.2/spl times/10/sup -6/ A/cm/sup 2/ and a value of V/sub oc/, as high as 344 mV at 3 A/cm/sup 2/ were measured.
Numerical and experimental investigation on air distributor design of fluidized bed reactor of sawdust pyrolysis
Abstract An improved biomass conversion in a lab-scale fluidized bed reactor (FBR) is achieved by optimizing the air distributor orifice size and number. Two approaches for introducing air were numerically and experimentally examined. These included perforated plate and downward orifice sparger. 3 mm and 5 mm orifice diameters, and 7, 9 and 13 holes were simulated at flow velocities of 2, 4, 6, and 8 times the minimum fluidization velocity, Umf. The simulation results revealed that increasing the orifice number has a positive effect on gas holdup, particularly for the perforated plate, which showed a uniform distribution of bubbles. The sparger configuration produced larger bubbles sizes, which could lead to better recirculation of solid flux, while stagnant particle zones were observed at the lower section of both distributors. A pyrolysis unit is also inserted at the top of freeboard of the FBR. For perforated plate with 6Umf, the pyrolysis process achieved thermal and cold gas efficiencies of 82.91% and 52.03%, respectively, while combustible gases with 41.6%mol CO, 8.7%mol CH 4 and 2.17%mol HC, were obtained. For sparger pipe and 6U mf _sp, 35.33 ppm NOx and 111 ppm SO 2 were measured in flue gas from combustion process at bed region.