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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Preparation and Characterization of Ribonucleic Acid (RNA)/Inorganic Materials Interfaces Using Photoemission Spectroscopy

Doran, Brian, 10 May 2004 (has links)
The objective of this master s thesis is the preparation and characterization of ribonucleic acid (RNA)/inorganic material interfaces by electrospray deposition and photoemission spectroscopy. This was done through investigation of the chemical and electronic structure of the surface of Highly Ordered Pyrolytic Graphite (HOPG) and gold before and after multiple steps of RNA thin film deposition by electrospray. Great interest has been shown by researchers into RNA due to its self-assembling ability. A series of experiments was conducted depositing RNA Poly adenosine, RNA Poly cytidine, and (for control purposes) DI water on HOPG. RNA Poly adenosine was also deposited on Gold. Gold is a more practical surface for use with RNA, but HOPG is useful for this study because it allows the precise determination of the density of states (DOS) of RNA. X-ray photoemission spectroscopy (XPS) and ultraviolet photoemission spectroscopy (UPS) were used to characterize the RNA-interfaces. The work function, high binding energy cutoff, and HOMO energies were determined. The clean, in-vacuum deposition of RNA was carried out using an electrospray thin film deposition device. The HOPG and gold substrates were prepared by in-situ cleavage and sputtering respectively. The electrospray method can be used for many different types of molecules including Polymers, metal-organics, crystals, and biological materials including RNA or DNA. These measurements provided data that will be helpful in determining the electronic properties of biological and substrate interfaces.
2

Charakterizace vlastností perovskitovských fotovoltaických článků / Photoimpedace spectroscopy characterization of the perovskit photovoltaic cells

Henek, Tomáš January 2018 (has links)
This work studies the subject of perovskite solar cells. The structure of perovskites is described along with a portion of photovoltaics history that led to the employment of perovskites as absorpsion layers. Further, methods of measurement for solar cells such as impedance spectroscopy, photospectroscopy and load characteristics are summarized. Lastly there is a description of already done analytics of perovskite solar cells with the summary of the results. In the practical part, there are measurements made to find out any effect of cell topology or light source wavelength on the cell performance.

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