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Chemical studies on SYNTHOIL process. Sixth quarterly report, December 1, 1976--March 1, 1977. [Catalyst improvement; mineral matter effects; preheated studies; 8 refs; Co molybdate]

Description: In support of the Pittsburgh Energy Research Center's SYNTHOIL Process for coal liquefaction, Sandia Laboratories has undertaken three tasks: Catalyst Improvement, Mineral Matter Effects, and Preheater Studies. In the last quarter, the catalyst improvement studies focused on the effects of nitrogen-containing compounds on the activity of presulfided cobalt molybdate catalyst pellets. Data from pulsed microreactor experiments have shown that pyridine, aniline, and pyrrole cause a decrease in the hydrodesulfurization of thiophene. In most cases these losses in activity were, to a great extent, reversible. In the mineral matter effects studies, chemical removal of pyrite and other mineral constituents has been carried out on Kentucky, West Virginia and Indiana coals. These coals were hydroliquefied in a batch autoclave. The viscosities and preasphaltene contents of the resulting liquid products were higher than those obtained from the original, untreated coals. The continuous reactor used for the preheater studies has been completed, and preliminary pressure testing has been started. The first shakedown run is expected in April.
Date: April 1, 1977
Creator: Holloway, P. H.; Granoff, B. & Nowak, E. J.
Partner: UNT Libraries Government Documents Department

Auger-electron line-shape study of CVD silicon nitride films

Description: The shapes of integral Auger-electron signals from chemical-vapor-deposited silicon nitride with 0.3 at percent and 12 at percent oxygen have been compared with each other and with signals from clean Si and SiO/sub 2/. The data show the probable existence of elementally bound Si in the nitrides. Incorporation of oxygen decreases the structure associated with elemental Si but does not cause the Si L/sub 2/,/sub 3/ VV line shape to change to that characteristic of SiO/sub 2/. The nitrogen peak shape was not affected by the increase in oxygen content to 12 at percent, but the shape of the oxygen signal, and its energy location in silicon nitride is considerably different than for oxygen in SiO/sub 2/. These data indicate that a detailed investigation of silicon nitride could lead to a better understanding of properties important to passivation and memory.
Date: May 1, 1977
Creator: Madden, H. H.; Moore, G. & Holloway, P. H.
Partner: UNT Libraries Government Documents Department

Future CIS Manufacturing Technology Development: Final Report, 8 July 1998--17 October 2001

Description: The University of Florida served as the basis for educating 12 graduate students in the area of photovoltaics engineering and research with a focus on thin-film CIS manufacturing technologies. A critical assessment of the thermodynamic data and of the phase diagrams for the Cu-Se and In-Se binary systems were carried out. We investigated the use of two novel precursor structures that used stacked In-Se and Cu-Se binary layers instead of conventional elemental layers, followed by rapid thermal processing (RTP) to produce CIS films. We investigated the evolution of electrical and microstructural properties of sputter-deposited ZnO:Al thin films. An assessment of the thermodynamics of the pseudobinary Cu2Se-Ga2Se3 system was done by using available experimental data, as well as an empirical method for estimating interactions in semiconductor solid solutions. Optimization studies were conducted to characterize the RTP of binary bilayer precursors for CIS synthesis using a newly acquired AG Associates Heatpulse furnace. Progress was made on the calculation of the 500C isothermal section of the phase diagram of the ternary Cu-In-Se system. Pursuit of developing alternative buffer layers for Cd-free CIS-based solar cells using a chemical-bath deposition (CBD) process has resulted in specific recipes for deposition. A rigorous model has been derived to predict the metal mass fluxes produced by conical thermal effusion sources. A two-dimensional model of the heat transfer was developed to model the substrate temperature distribution in the UF PMEE Reactor that features a rotating platen/substrates and effusion sources. We have grown and characterized polycrystalline CIS epitaxial films on single-crystal GaAs substrates under conditions that enhance the influence of surface effects on the resulting films and their properties. Progress was made on the study of CIS and CGS single-crystal growth, along with accompanying morphological and compositional characterizations. We have developed physical models and performed numerical simulations using AMP-1D program ...
Date: June 1, 2003
Creator: Anderson, T. J.; Crisalle, O. D.; Li, S. S. & Holloway, P. H.
Partner: UNT Libraries Government Documents Department

The role of gallium sulfide in SrS:Ce grain growth

Description: Whereas efficient red (ZnS:Mn) and green (ZnS:Tb) phosphors are available for full-color flat-panel display technology, efficient blue phosphors are still under development. SrS:Ce is being investigated as a suitable material. As part of a larger study, annealed SrS:Ce films produced from sputter targets incorporating Ga{sub 2}S{sub 3} were found to be five times brighter than films produced from targets containing no Ga{sub 2}S{sub 3}. Consequently, the significance of added gallium sulfide to the morphology of SrS:Ce films during annealing is being investigated. Following deposition, plan view specimens of films were prepared for transmission electron microscopy by mechanical grinding, dimpling, and Ar{sup +} milling. Films were examined in a Philips CM12, and a JEOL 200CX. Additionally, EDS line scans were obtained in the scanning-transmission mode of a Philips CM200FEG, integrated with an EMiSPEC Vision acquisition system. The EDS line scans were defined as a series of 40 points along a line, spaced approximately 3.6 nm apart. The dwell time for EDS acquisition at each point was 10 sec. It was found that the addition of Ga{sub 2}S{sub 3} increases the brightness of SrS:Ce films by enhancing grain growth during annealing. Also being investigated is the possibility that Ga{sub 2}S{sub 3}, either as a sub-sulfide or as a source of Ga, is involved in a liquid-phase sintering mechanism, which would account for the increased grain growth observed after annealing.
Date: April 1, 1997
Creator: Evans, N.D.; Naman, A.; Jones, K.S.; Holloway, P.H. & Rice, P.M.
Partner: UNT Libraries Government Documents Department