Browsing by Subject "Structural design"

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    Electronic and optical properties of 4.2 μm"N" structured superlattice MWIR photodetectors
    (Elsevier, 2013) Salihoglu, O.; Hostut M.; Tansel, T.; Kutluer, K.; Kilic A.; Alyoruk, M.; Sevik, C.; Turan, R.; Ergun, Y.; Aydınlı, Atilla
    We report on the development of a new structure for type II superlattice photodiodes that we call the "N" design. In this new design, we insert an electron barrier between InAs and GaSb in the growth direction. The barrier pushes the electron and hole wavefunctions towards the layer edges and under bias, increases the overlap integral by about 25% leading to higher detectivity. InAs/AlSb/GaSb superlattices were studied with density functional theory. Both AlAs and InSb interfaces were taken into account by calculating the heavy hole-light hole (HH-LH) splittings. Experiments were carried out on single pixel photodiodes by measuring electrical and optical performance. With cut-off wavelength of 4.2 μm at 120 K, temperature dependent dark current and detectivity measurements show that the dark current is 2.5 × 10 -9 A under zero bias with corresponding R0A resistance of 1.5 × 104 Ω cm2 for the 500 × 500 μm2 single pixel square photodetectors. Photodetector reaches BLIP condition at 125 K with the BLIP detectivity (DBLIP) of 2.6 × 10 10 Jones under 300 K background and -0.3 V bias voltage. © 2012 Elsevier B.V. All rights reserved.
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    Modelling detailed information flows in building design with the parameter-based design structure matrix
    (Elsevier, 2006-01) Tasli Pektas, S.; Pultar M.
    The Architecture/Engineering/Construction (AEC) industry is one of the multidisciplinary domains in which collaboration among related parties is of utmost importance. Despite the intense flow of information between design professionals, there is a lack of research to better understand and manipulate these flows. Most of the current process modelling tools in the AEC industry do not enable analyses of iterative information cycles. Moreover, these tools represent the process at high levels, thus, they are inadequate for multi-parameter problems like building design. With a view to alleviate these problems, this paper introduces the use of parameter-based design structure matrix as a process modelling and system analysis tool for building design. The method reveals insights into the process structure, optimum sequence of parameter decisions, iterative cycles and concurrency in the process. The application of the method is demonstrated through a case study on suspended ceiling design in a real-life project.