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Recovery Act: Near-Single-Crystalline Photovoltaic Thin Films on Polycrystalline, Flexible Substrates

Description: III-V photovoltaics have exhibited efficiencies above 40%, but have found only a limited use because of the high cost of single crystal substrates. At the other end of the spectrum, polycrystalline and amorphous thin film solar cells offer the advantage of low-cost fabrication, but have not yielded high efficiencies. Our program is based on single-crystalline-like thin film photovoltaics on polycrystalline substrates using biaxially-textured templates made by Ion Beam-Assisted Deposition (IBAD)… more
Date: November 29, 2010
Creator: Selvamanickam, Venkat & Freundlich, Alex
Partner: UNT Libraries Government Documents Department
open access

Process Development for CIGS Based Thin Film Photovoltaics Modules, Phase II Technical Report

Description: As a technology partner with NREL, Global Solar Energy (GSE) has initiated an extensive and systematic plan to accelerate the commercialization of thin-film photovoltaics (PV) based on copper indium gallium diselenide (CIGS). The distinguishing feature of the GSE manufacturing process is the exclusive use of lightweight, flexible substrates. GSE has developed the technology to fabricate CIGS photovoltaics on both stainless-steel and polymer substrates. CIGS deposited on flexible substrates can … more
Date: November 9, 2000
Creator: Britt, J.; Wiedeman, S. & Albright, S.
Partner: UNT Libraries Government Documents Department
open access

Sequential Purification and Crystal Growth for the Production of Low Cost Silicon Substrates: Quarterly Technical Progress Report No. 3, April 1 - June 30, 1980

Description: The objective of this program is to identify and develop low cost processing for fabricating large grain size polycrystalline silicon substrates. Metallurgical grade silicon (MG-Si) is chosen as the starting material for sequential purification and crystal growth. As shown in the previous two technical reports, several purification techniques have been studied. They include (l) acid leaching with HCl, (2) physical separation of insoluble impurities, (3) reactive gas treatment of molten silicon,… more
Date: August 1, 1980
Creator: Liaw, M. & Secco D'Aragona, F.
Partner: UNT Libraries Government Documents Department
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Controlled Growth of Carbon Nanotubes on Conductive Metal Substrates for Energy Storage Applications

Description: The impressive mechanical and electronic properties of carbon nanotubes (CNTs) make them ideally suited for use in a variety of nanostructured devices, especially in the realm of energy production and storage. In particular, vertically-aligned CNT “forests” have been the focus of increasing investigation for use in supercapacitor electrodes and as hydrogen adsorption substrates. Vertically-aligned CNT growth was attempted on metal substrates by waterassisted chemical vapor deposition (CVD). CNT… more
Date: January 1, 2009
Creator: Brown, P. & Engtrakul, C.
Partner: UNT Libraries Government Documents Department
open access

Printability and inspectability of programmed pit defects on teh masks in EUV lithography

Description: Printability and inspectability of phase defects in ELlVL mask originated from substrate pit were investigated. For this purpose, PDMs with programmed pits on substrate were fabricated using different ML sources from several suppliers. Simulations with 32-nm HP L/S show that substrate pits with below {approx}20 nm in depth would not be printed on the wafer if they could be smoothed by ML process down to {approx}1 nm in depth on ML surface. Through the investigation of inspectability for program… more
Date: March 12, 2010
Creator: Kang, I. Y.; Seo, H. S.; Ahn, B. S.; Lee, D. G.; Kim, D.; Huh, S. et al.
Partner: UNT Libraries Government Documents Department
open access

Platinum(II)-Catalyzed Ethylene Hydrophenylation: Switching Selectivity between Alkyl- and Vinylbenzene Production

Description: Article discussing platinum(II)-catalyzed ethylene hydrophenylation and the influence of dipyridyl chelate ring size on catalyst activity and longevity.
Date: unknown
Creator: McKeown, Bradley A.; Gonzalez, Hector Emanuel; Friedfeld, Max R.; Brosnahan, Anna M.; Gunnoe, T. Brent; Cundari, Thomas R., 1964- et al.
Partner: UNT College of Arts and Sciences
open access

Mesoscopic structure conditions the emergence of cooperation on social networks

Description: We study the evolutionary Prisoner's Dilemma on two social networks substrates obtained from actual relational data. We find very different cooperation levels on each of them that cannot be easily understood in terms of global statistical properties of both networks. We claim that the result can be understood at the mesoscopic scale, by studying the community structure of the networks. We explain the dependence of the cooperation level on the temptation parameter in terms of the internal struct… more
Date: December 1, 2008
Creator: Lozano, S.; Arenas, A. & Sanchez, A.
Partner: UNT Libraries Government Documents Department
open access

Long term biosustainability in a high energy, low diversity crustal biome

Description: Geochemical, microbiological, and molecular analyses of alkaline saline groundwater at 2.8 kilometers depth in Archaean metabasalt revealed a microbial biome dominated by a single phylotype affiliated with thermophilic sulfate reducers belonging to Firmicutes. These sulfate reducers were sustained by geologically produced sulfate and hydrogen at concentrations sufficient to maintain activities for millions of years with no apparent reliance on photosynthetically derived substrates.
Date: October 1, 2006
Creator: Lin, L-H.; Wang, P-L.; Rumble, D.; Lippmann-Pipke, J.; SherwoodLollar, B.; Boice, E. et al.
Partner: UNT Libraries Government Documents Department
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Enantioselective Catalysis of the Aza-Cope Rearrangement by a Chiral Supramolecular Assembly

Description: The chiral supramolecular catalyst Ga{sub 4}L{sub 6} [L = 1,5-bis(2,3-dihydroxybenzoylamino)naphthalene] is a molecular tetrahedron that catalyzes the 3-aza-Cope rearrangement of allyl enammonium cations. This catalysis is accomplished by preorganizing the substrate in a reactive conformation within the host. This work demonstrates that through the use of enantiopure assembly, its chiral cavity is capable of catalyzing the 3-aza-Cope rearrangement enantioselectively, with yields of 21-74% and e… more
Date: July 29, 2009
Creator: Brown, Casey J.; Bergman, Robert G. & Raymond, Kenneth N.
Partner: UNT Libraries Government Documents Department
open access

Quasi-Freestanding multilayer graphene films on the carbon face of SiC

Description: The electronic band structure of as-grown and doped graphene grown on the carbon face of SiC is studied by high-resolution angle-resolved photoemission spectroscopy, where we observe both rotations between adjacent layers and AB-stacking. The band structure of quasi-freestanding AB-bilayers is directly compared with bilayer graphene grown on the Si-face of SiC to study the impact of the substrate on the electronic properties of epitaxial graphene. Our results show that the C-face films are near… more
Date: June 30, 2010
Creator: Siegel, D. A.; Hwang, C. G.; Fedorov, A. V. & Lanzara, A.
Partner: UNT Libraries Government Documents Department
open access

Reactions of a Ru(II) Phenyl Complex with Substrates that Possess C-N or C-O Multiple Bonds: C-C Bond Formation, N-H Bond Cleavage, and Decarbonylation Reactions

Description: Article on the reactions of an Ru(II) phenyl complex with substrates that possess C-N or C-O multiple bonds and C-C bond formation, N-H bond cleavage, and decarbonylation reactions.
Date: February 8, 2006
Creator: Lee, John P.; Pittard, Karl A.; DeYonker, Nathan J.; Cundari, Thomas R., 1964-; Gunnoe, T. Brent & Petersen, Jeffrey L.
Partner: UNT College of Arts and Sciences
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Redox Non-Innoence Permits Catalytic Nitrene Carbonylation by (dadi)Ti=NAd (Ad = Adamantyl)

Description: This article describes (dadi)Ti(X/L) species that manifest redox non-innocence (RNI), including a rare instance in which carbon monoxide does not affect redox activity at the metal, and does not bind, thus permitting its use as a substrate in catalysis.
Date: March 3, 2017
Creator: Heins, Spencer P.; Wolczanski, Peter T.; Cundari, Thomas R., 1964- & MacMillan, Samantha N.
Partner: UNT College of Arts and Sciences
open access

Molten salt-based growth of bulk GaN and InN for substrates.

Description: An atmospheric pressure approach to growth of bulk group III-nitrides is outlined. Native III-nitride substrates for optoelectronic and high power, high frequency electronics are desirable to enhance performance and reliability of these devices; currently, these materials are available in research quantities only for GaN, and are unavailable in the case of InN. The thermodynamics and kinetics of the reactions associated with traditional crystal growth techniques place these activities on the ex… more
Date: August 1, 2007
Creator: Waldrip, Karen Elizabeth
Partner: UNT Libraries Government Documents Department
open access

Kinetics and Mechanisms of Calcite Reactions with Saline Waters

Description: 1. Objective The general objective of this research was to determine the kinetics and mechanisms of calcite reactions with saline waters over a wide range of saline water composition, carbon dioxide partial pressure (pCO2), and modest ranges of T and P. This would be done by studying both reaction rates and solubility from changes in solution chemistry. Also, nanoscale observations of calcite surface morphology and composition would be made to provide an understanding of rate controlling mecha… more
Date: November 15, 2010
Creator: Chapman, Piers & Morse, John W.
Partner: UNT Libraries Government Documents Department
open access

Final Report for Department of Energy/EERE (for public release)

Description: Developing CIGS solar cells calls for the understanding of materials and processing in order to translate the record small efficiency to module and the strategy to produce thin cells for materials and processing saving. This project has exploited nanostructuring of CIG solar cells, including nanowires and nanotextured substrates. We showed that nanowires function as well-defined CIGS-CdS p-n junction for understanding the chemical fluctuation, defect formation interface and grain boundary behav… more
Date: April 30, 2012
Creator: Cui, Yi
Partner: UNT Libraries Government Documents Department
open access

Characterization of Arthrobacter Globiformis Aspartate Transcarbamylase Concentrations of Substrates

Description: This thesis consists of one major section with two subsections. The first subsection investigates the activity of Arthrobacter globiformis aspartate transcarbamylase's specific activity with increasing concentrations of the enzyme's substrate. Dihydroorotase (DHOase) activity was also measured with increasing concentrations of the substrate dihydroorotate. The second subsection collected data in order to classify the enzyme, resulting in a classification into the category of class A ATCases … more
Date: December 2012
Creator: Wright, Jackie
Partner: UNT Libraries
open access

Facile and Regioselective C H Bond Activation of Aromatic Substrates by an Fe (II) Complex Involving a Spin-Forbidden Pathway

Description: Article discussing facile and regioselective C H bond activation of aromatic substrates by an Fe(II) complex involving a spin-forbidden pathway.
Date: unknown
Creator: Kalman, Steven E.; Petit, Alban; Gunnoe, T. Brent; Ess, Daniel H.; Cundari, Thomas R., 1964- & Sabat, Michal
Partner: UNT College of Arts and Sciences
open access

Sculpting the shape of semiconductor heteroepitaxial islands: fromdots to rods

Description: In the Ge on Si model heteroepitaxial system, metal patterns on the silicon surface provide unprecedented control over the morphology of highly ordered Ge islands. Island shape including nanorods and truncated pyramids is set by the metal species and substrate orientation. Analysis of island faceting elucidates the prominent role of the metal in promoting growth of preferred facet orientations while investigations of island composition and structure reveal the importance of Si-Ge intermixing in… more
Date: June 20, 2006
Creator: Robinson, J. T.; Walko, D. A.; Arms, D. A.; Tinberg, D. S.; Evans, P. G.; Cao, Y. et al.
Partner: UNT Libraries Government Documents Department
open access

Spin-on-glass coatings for the generation of super-polishedsubstrates for extreme ultraviolet optics

Description: Substrates intended for use as extreme ultraviolet (EUV) optics have extremely stringent requirements in terms of finish. These requirements can dramatically increase the cost and fabrication time, especially when non-conventional shapes, such as toroids, are required. Here we present a spin-on-glass resist process capable of generating super-polished parts from inexpensive substrates. The method has been used to render diamond-turned substrates compatible for use as EUV optics. Toroidal diamon… more
Date: January 1, 2005
Creator: Salmassi, Farhad; Naulleau, Patrick P. & Gullikson, Eric M.
Partner: UNT Libraries Government Documents Department
open access

Extreme ultraviolet mask substrate surface roughness effects on lithography patterning

Description: In extreme ultraviolet lithography exposure systems, mask substrate roughness induced scatter contributes to LER at the image plane. In this paper, the impact of mask substrate roughness on image plane speckle is explicitly evaluated. A programmed roughness mask was used to study the correlation between mask roughness metrics and wafer plane aerial image inspection. We find that the roughness measurements by top surface topography profile do not provide complete information on the scatter relat… more
Date: June 21, 2010
Creator: George, Simi; Naulleau, Patrick; Salmassi, Farhad; Mochi, Iacopo; Gullikson, Eric; Goldberg, Kenneth et al.
Partner: UNT Libraries Government Documents Department
open access

Reactions of TpRu(CO) (NCMe) (Me) (Tp = Hydridotris(pyrazolyl)borate) with Heteroaromatic Substrates: Stoichiometric and Catalytic C-H Activation

Description: Article discussing reactions of TpRu(CO)(NCMe)(Me) (Tp = Hydridotris(pyrazolyl)borate) with heteroaromatic substrates and stoichiometric and catalytic C-H activation.
Date: October 15, 2004
Creator: Pittard, Karl A.; Lee, John P.; Cundari, Thomas R., 1964-; Gunnoe, T. Brent & Petersen, Jeffrey L.
Partner: UNT College of Arts and Sciences
open access

Actinic imaging of native and programmed defects on a full-field mask

Description: We describe the imaging and characterization of native defects on a full field extreme ultraviolet (EUV) mask, using several reticle and wafer inspection modes. Mask defect images recorded with the SEMA TECH Berkeley Actinic Inspection Tool (AIT), an EUV-wavelength (13.4 nm) actinic microscope, are compared with mask and printed-wafer images collected with scanning electron microscopy (SEM) and deep ultraviolet (DUV) inspection tools. We observed that defects that appear to be opaque in the SEM… more
Date: March 12, 2010
Creator: Mochi, I.; Goldberg, K. A.; Fontaine, B. La; Tchikoulaeva, A. & Holfeld, C.
Partner: UNT Libraries Government Documents Department
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