Growth and Characterisation of Radio Frequency Magnetron Sputttered Indium Tin Oxide Thin Films

The increasing interest in the interaction of light with electricity and electronically active materials made the materials and techniques for producing semitransparent electrically conducting films particularly attractive. Transparent conductors have found major applications in a number of electronic and optoelectronic devices including resistors, transparent heating elements, antistatic and electromagnetic shield coatings, transparent electrode for solar cells, antireflection coatings, heat reflecting mirrors in glass windows and many other. Tin doped indium oxide (indium tin oxide or ITO) is one of the most commonly used transparent conducting oxides. At present and likely well into the future this material offers best available performance in terms of conductivity and transmittivity combined with excellent environmental stability, reproducibility and good surface morphology. Although partial transparency, with a reduction in conductivity, can be obtained for very thin metallic films, high transparency and simultaneously high conductivity cannot be attained in intrinsic stoichiometric materials. The only way this can be achieved is by creating electron degeneracy in a wide bandgap (Eg > 3eV or more for visible radiation) material by controllably introducing non-stoichiometry and/or appropriate dopants. These conditions can be conveniently met for ITO as well as a number of other materials like Zinc oxide, Cadmium oxide etc. ITO shows interesting and technologically important combination of properties viz high luminous transmittance, high IR reflectance, good electrical conductivity, excellent substrate adherence and chemical inertness. ITO is a key part of solar cells, window coatings, energy efficient buildings, and flat panel displays. In solar cells, ITO can be the transparent, conducting top layer that lets light into the cell to shine the junction and lets electricity flow out. Improving the ITO layer can help improve the solar cell efficiency. A transparent ii conducting oxide is a material with high transparency in a derived part of the spectrum and high electrical conductivity. Beyond these key properties of transparent conducting oxides (TCOs), ITO has a number of other key characteristics. The structure of ITO can be amorphous, crystalline, or mixed, depending on the deposition temperature and atmosphere. The electro-optical properties are a function of the crystallinity of the material. In general, ITO deposited at room temperature is amorphous, and ITO deposited at higher temperatures is crystalline. Depositing at high temperatures is more expensive than at room temperature, and this method may not be compatible with the underlying devices. The main objective of this thesis work is to optimise the growth conditions of Indium tin oxide thin films at low processing temperatures. The films are prepared by radio frequency magnetron sputtering under various deposition conditions. The films are also deposited on to flexible substrates by employing bias sputtering technique. The films thus grown were characterised using different tools. A powder x-ray diffractometer was used to analyse the crystalline nature of the films. The energy dispersive x-ray analysis (EDX) and scanning electron microscopy (SEM) were used for evaluating the composition and morphology of the films. Optical properties were investigated using the UVVIS- NIR spectrophotometer by recording the transmission/absorption spectra. The electrical properties were studied using vander Pauw four probe technique. The plasma generated during the sputtering of the ITO target was analysed using Langmuir probe and optical emission spectral studies.

Harry Clarke e a literatura: da pintura em vitrais à ilustração de livros

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Partenheim versus Boppard : Geschichte und Rekonstruktion zweier spätgotischer Verglasungen am Mittelrhein

Im Mittelpunkt der vorliegenden Arbeit stehen zwei spätgotische Verglasungen aus der Region des Mittelrheins, die bislang zumeist aus stilistischen Gründen mehr oder weniger eng miteinander verknüpft worden sind. Die Partenheimer Scheiben entstanden für die nach 1435 erneuerte Pfarrkirche des gleichnamigen Ortes in Rheinhessen, die Bopparder Fenster waren für das ab 1440 errichtete Seitenschiff der dortigen Karmeliterkirche bestimmt. Beide Zyklen wurden bereits im frühen 19. Jahrhundert ihren ursprünglichen Standorten entfremdet. Der Partenheimer Bestand gelangte vor allem in das Hessische Landesmuseum von Darmstadt. Die Bopparder Glasmalereien haben sich mittlerweile weltweit über Museen und Privatsammlungen verstreut. Im Nachzeichnen der dabei gewählten Wege liegt einer der Schwerpunkte der Arbeit, im Feststellen der zugleich vorgenommenen Strukturveränderungen ein weiterer. Die nicht zuletzt auf dieser Basis erstellten Vorschläge zur Rekonstruktion der einst in situ bestehenden Verhältnisse erlauben dabei vor allem dem Bopparder Komplex eine Präzisierung oder sogar Korrektur von früheren Annahmen: Datieren lassen sich die Karmeliterfenster nunmehr in die Jahre zwischen 1443 und 1446. Zu ihren Stiftern zählten neben dem Trierer Erzbischof Jakob v. Sierck offenbar ausschließlich der lokale Adel sowie diverse Bruderschaften der Stadt inklusive einzelner Vertreter derselben. Das wichtigste Fazit dieser Neubestimmung ist deshalb die regionale Verankerung der Fenster. Nicht zu bestätigen ist die vormals postulierte Werkstattgemeinschaft beider Zyklen: Der um 1440 geschaffene Kernbestand von Partenheim scheint im Rhein-Main-Gebiet verwurzelt und nur das nördlichste Chorfenster wurde nach etwa zehnjähriger Pause von anderen Glasmalern ausgeführt. Den Bopparder Auftrag teilten sich stattdessen von vornherein eine vielleicht in Koblenz ansässige Werkstatt sowie ein in Lothringen tätiges Atelier. Vollkommen eigenständig sind die Zyklen von Partenheim und Boppard damit gleichwohl exemplarische Vertreter für die stilistische Vielfalt am Mittelrhein im 15. Jahrhundert.

The energy of Beverly Rosen artist, professor, risk taker

"This paper takes a look at Beverly Rosen’s artistic work, providing an overview of the various periods and styles she explored, while introducing new details and expanding established interpretations of her work. It is an attempt at documenting Rosen’s many activities in addition to her personal art and professional development. Special attention is given to exhibitions and programming held at Rosen’s gallery, St. Charles on Wazee"

The execution of the mural arts of the West

"This thesis describes and explains the execution of the casein mural, 'Arts of the West'. The artist's project was to prepare a casein mural for the Pioneer Room of the New Student Union at the University of Denver."

The Rueter-Hess Dam and Reservoir Project: A Question of Sustainable Water

Water in sufficient quantities throughout the Colorado Front Range is becoming increasingly limited. This paper examines the consequences for continued unsustainable use of water for communities of the Denver metropolitan area. This paper also looks at the effect that water law in the West has for otherwise optimum distributions of water. In addition, four regional and state water studies are reviewed for their contribution to sustainable water. Finally, the Final Environmental Impact Statement of the Rueter-Hess dam and reservoir project in Parker, Colorado is explored. Key findings conclude that the Rueter-Hess project may not, by itself, provide sustainable water for Parker; but the project will create incentive and opportunity for communities throughout the region to address the question of sustainable water.

Bowl with Kufic inscription and tree motif

Glass, Islamic, Fatamid; 4 7/32 in. x 6 1/32 in.; blown glass and stained glass with copper and silver stains