The continuous trend towards mega-functional, high-performance and ultra-miniaturized system has been driving the need for advances in novel materials with superior properties leading to thin components, high-density interconnect substrates and interconnections. Power supply and management is becoming a critical bottleneck for the advances in such mega-functional systems because power components do not scale down with the rest of the system resulting in bulky and stand-alone power modules. Amongst the power components, thin film capacitors are considered the most challenging to integrate because of several manufacturability concerns. The challenges are related to process compatibility of high permittivity dielectrics with substrates and high surface area electrodes, yield, leakage and losses. This thesis focuses on novel thin film capacitor technologies that address some of these critical challenges. / Thesis advisor has approved the addition of errata to this item. The abstract text in the metadata record has been modified to match the document text.

The literature review indicates that studies on the structures and properties of perovskites materials have shown attractive applications in the fields of energy, catalysts and sensing materials for fuel cell and sensing industries. Kinetic phenomena in thin film systems, such as solid state amorphization and interface reactions due to diffusion during thin film deposition, are introduced indicating that thermal stability is a concern in thin film sensor device application. The principle of traditional methods of materials characterization is briefly discussed. Emphasis is placed on the functions of analytical transmission electron microscopy. / The SrFeO3/SiO2/Si and SrFeO3/Al 2O3 thin film systems have been studied using transmission electron microscopy. The thin films of SrFeO3 were grown by pulsed laser deposition. For the SrFeO3/SiO2/Si system, TEM characterization showed that the microstructure of the film deposited at room temperature contained crystalline and amorphous layers. Silicon diffusion into SrFeO3 films occurred at the SiO2 interface. The silicon-induced interfacial reactions resulted in phase transformations and the growth of complex crystalline and amorphous phases. The principal compositions of these phases were Sr(Fe,Si)12O19, SrOx and amorphous [Sr-Fe-Si-O]. / The films in the SrFeO3/Al2O3 system were deposited onto single crystal and sintered polycrystalline Al2O 3 substrates at room temperature and 700°C and subjected to annealing for various periods of time at 700-1000°C. TEM characterization showed that the morphology of the film varied with changes in deposition temperature: a columnar structure was produced at room temperature and layers containing crystalline grains were produced at 700°C. The interfacial structures of the films remained unchanged below 700°C. Interfacial reactions were observed following annealing at 850°C for 5 hours. The phase transformation at the interface was characterized for the film annealed at 1000°C for 5 hours, for which the principal phases were identified as SrAl2-xFe xO4 and SrFe12-yAlyO19. As a result, an isothermal section at 1000°C of a ternary phase diagram for SrO-Al2O3-Fe2O3 is proposed. Evaluation for thin film conductometric sensing applications indicated that the untreated films deposited at 700°C onto both single crystal and sintered Al2O3 substrates exhibited a similar temperature dependency of conductivity in air and a p-type gas sensor response to oxygen and propane at 500°C.

In this thesis, intrinsic hydrogenated nanocrystalline silicon thin films for solar cells application have been deposited by means of the hot &ndash / wire chemical vapour deposition (HWCVD) technique and have been characterised for their performance. It is noticed that&nbsp / hydrogenated nanocrystalline silicon is similar in some aspects (mainly optical) to its counterpart amorphous silicon actually used as the intrinsic layer in the photovoltaic industry. Substantial differences between the two materials have been found however in their respective structural and electronic properties.<br /> <br /> We show that hydrogenated nanocrystalline silicon retains good absorption coefficients known for amorphous silicon in the visible region. The order improvement and a reduced content of the bonded hydrogen in the films are linked to their good stability. We argue that provided a moderate hydrogen dilution ratio in the monosilane gas and efficient process pressure in the deposition chamber, intrinsic hydrogenated nanocrystalline silicon with photosensitivity better than 102 and most importantly resistant to the Staebler Wronski effect (SWE) can be produced. <br /> <br /> This work explores the optical, structural and electronic properties of this promising material whose study &ndash / samples have been exclusively produced in the HWCVD reactors based in the Solar Cells laboratory of the Physics department at the University of the Western Cape.

Thesis (MEng)--University of South Australia, 1997

Photovoltaics (PV) is fast emerging as an attractive renewable energy technology due to concerns of global warming, pollution and scarcity of fossil fuel supplies. However to compete in the global energy market, solar cells need to be cheaper and more energy efficient. Silicon is the favorite semiconductor used in solar photovoltaic cells because of its ubiquity and established technology, but due to its indirect bandgap silicon is a poor absorber and light emitter. Thin film cells play an important role in low cost photovoltaics, but at the cost of reduced efficiencies when compared to wafer based cells. There remains much untapped potential in thin-film solar cells which this work has attempted to exploit through exploring novel approaches of enhancing the efficiency of thin film cells using the optical properties of sub-wavelength metal nanoparticles. Metals are considered as strong absorbers of light because of their large free-electron density. How can metals improve light trapping in solar cells? This question has raised several eyebrows and this thesis is an attempt to show that metal nanoparticles can be useful in producing efficient solar cells. Subwavelength metal particles support surface modes called surface plasmons when light is incident on them, which cause the particles to strongly scatter light into the underlying waveguide or substrate, enhancing absorption. The process of coupling thin film silicon waveguide modes to plasmonic metals using unpolarised light at normal incidence is applied to silicon-based solar cells and light emitting diodes, and enhanced photocurrent and electroluminescence is realized with potential for further optimisation and improvement. The results from this study correspond to a current increase of up to 19% from planar wafer based cells and up to 33% increase from 1.25 micron thin-film silicon-on-insulator structures for the AM1.5 global spectrum. We also report for the first time an up to twelve fold increase in electroluminescence signal from 95nm thick light-emitting diodes. From the results we conclude that this method which involves simple techniques of nanoparticle deposition and characterization could hold important implications in the improvement of thin-film silicon cell absorption / emission efficiencies where conventional methods of light trapping are not feasible, resulting in promising near-term applications of surface plasmons in photovoltaics and optoelectronics.

Thesis (M.S.)--Rochester Institute of Technology, 1989. / "References": leaves 20-23.

Thesis (Ph. D.)--University of California, San Diego, 1999. / Vita. Includes bibliographical references.

Thesis (M.S.)--Boise State University, 2009. / Includes abstract. Includes bibliographical references (leaves 124-131).

Thesis (Ph. D.)--Mechanical Engineering, Georgia Institute of Technology, 2009. / Committee Chair: Sitaraman, Suresh; Committee Member: Degertekin, Levent; Committee Member: McDowell, David; Committee Member: Tummala, Rao; Committee Member: Vandentop, Gilroy; Committee Member: Wang, Zhong Lin. Part of the SMARTech Electronic Thesis and Dissertation Collection.

Thesis (M.S.)--Boise State University, 2009. / Title from t.p. of PDF file (viewed June 1, 2010). Includes abstract. Includes bibliographical references (leaves 124-131).