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Minority carrier diffusion, defects, and localization in InGaAsN with 2% nitrogen

Description: Electron and hole transport in compensated, InGaAsN ({approx} 2% N) are examined through Hall mobility, photoconductivity, and solar cell photoresponse measurements. Short minority carrier diffusion lengths, photoconductive-response spectra, and doping dependent, thermally activated Hall mobilities reveal a broad distribution of localized states. At this stage of development, lateral carrier transport appears to be limited by large scale (>> mean free path) material inhomogeneities, not a… more
Date: May 3, 2000
Creator: Kurtz, Steven R.; Allerman, Andrew A.; Seager, Carleton H.; Sieg, Robert M. & Jones, Eric D.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Effects of chemical modifications on photophysics and exciton dynamics on {pi}-conjugation attenuated and metal-chelated photoconducting polymers

Description: Effects of two types of chemical modifications on photoconducting polymers consisting of polyphenylenevinylene (PPV) derivatives are studied by static and ultrafast transient optical spectroscopy as well as semi-empirical ZINDO calculations. The first type of modification inserts 2,2{prime}-bipyridyl-5-vinylene units (bpy V) in the PPV backbone, and the second type involves metal-chelation with the bpy sites. Photoluminescence and exciton dynamics of polymers 1 and 2 with PV:bpyV ratios of 1 an… more
Date: March 11, 2000
Creator: Chen, L. X.; Jager, W. J. H.; Gosztola, D. J.; Niemczyk, M. P. & Wasielewski, M. R.
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Partner: UNT Libraries Government Documents Department
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Photocharge transport and recombination measurements in amorphous silicon films and solar cells by photoconductive frequency mixing: Annual subcontract report, 20 April 1998--19 April 1999

Description: In the present phase of the program, the transport parameters of a number of amorphous semiconductors prepared by a number of techniques were determined by the photoconductive frequency mixing technique. This technique enabled the authors to determine the drift mobility, md, and the photomixing lifetime, t. The technique is based on the idea of heterodyne detection for photoconductors. When two similarly polarized monochromatic optical beams of slightly different frequencies are incident upon a… more
Date: February 28, 2000
Creator: Braunstein, R.; Kattwinkel, A.; Liebe, J. & Sun, G.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Photoconductive properties of GaAs{sub 1{minus}x}N{sub x} double heterostructures as a function of excitation wavelength

Description: The ternary semiconductor GaAs{sub 1{minus}x}N{sub x} with 0 < x < 0.3 can be grown epitaxially on GaAs and has a very large bowing coefficient. The alloy bandgap can be reduced to about 1.0 eV with about a 3% nitrogen addition. In this work, the authors measured the internal spectral response and recombination lifetime of a number of alloys using the ultra-high frequency photoconductive decay (UHFPCD) method. The data shows that the photoconductive excitation spectra of the GaAs{sub 0.97… more
Date: May 22, 2000
Creator: Ahrenkiel, R. K.; Mascarenhas, A.; Johnston, S. W.; Zhang, Y.; Friedman, D. J. & Vernon, S. M.
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Partner: UNT Libraries Government Documents Department
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Effect of magnetic field on GaAs photo-conductive detectors

Description: A photo-conductive detector (PCD) with active medium such as GaAs can be a useful plasma diagnostic, particularly in the EUV-to-soft X-ray regime. However, for laser-plasma or other high-bandpass applications, an important limitation can be a relatively long output decay time. A major (sometimes dominant) contributor to this tail is the electron-hole recombination time. This can be shortened with dopants or crystal damage (e.g., from neutron irradiation), but such lattice disruptions also decre… more
Date: August 1, 2000
Creator: Goldin, F. J. & McCrea, E.
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Partner: UNT Libraries Government Documents Department
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Interdisciplinary applications of Pauling's metallic orbital and unsynchronized resonance to problems of modern physical chemistry: Conductivity, magnetism, molecular stability, superconductivity, catalysis, photoconductivity, and chemical reactions

Description: No Description Available.
Date: December 8, 2000
Creator: Pavao, Antonio C.; Taft, Carlton A.; Guimaraes, Tereza C.F.; Leao, Marcelo B.C.; Mohallem, Jose R. & Lester Jr., William A.
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Partner: UNT Libraries Government Documents Department
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Longevity Improvement of Optically Activated, High Gain GaAs Photoconductive Semiconductor Switches

Description: The longevity of high gain GaAs photoconductive semiconductor switches (PCSS) has been extended to over 100 million pulses at 23A, and over 100 pulses at 1kA. This is achieved by improving the ohmic contacts by doping the semi-insulating GaAs underneath the metal, and by achieving a more uniform distribution of contact wear across the entire switch by distributing the trigger light to form multiple filaments. This paper will compare various approaches to doping the contacts, including ion impla… more
Date: March 2, 2000
Creator: Mar,Alan; Loubriel,Guillermo M.; Zutavern,Fred J.; O'Malley,Martin W.; Helgeson,Wesley D.; Brown,Darwin James et al.
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Partner: UNT Libraries Government Documents Department
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