Physics Commons^™

Flexible Electronics : Materials And Sensor Fabrication, Katherine J. Duncan

Dissertations

This dissertation demonstrates how to fabricate piezoelectric/pyroelectric thin films by using different printing techniques. These techniques could replace vacuum techniques for manufacturing piezoelectric/pyroelectric sensors. Ink-jet, screen and stencil printing techniques were developed to print these devices.

This work outlines attempts to develop a solution processable conductive ink for ink-jet printing. It then details the printing of commercial conductive ink on flexible substrates employing the three printing methods. Raman spectroscopy and Fourier transform infrared spectroscopy, are both used to investigate the structure of the P(VDF-TrFE) films. Optical microscopy is used to investigate the thickness and uniformity of the deposited films. The …

Synthesis And Characterization Of Plasma Enhanced Chemically Vapor Deposited Tantalum Films, Weizhong Chen

Dissertations

A low temperature inorganic plasma-enhanced chemical vapor deposition (PECVD) process has been developed for the growth of Ta using tantalum pentachloride (TaC15) as the preferred precursor and hydrogen as the reactant gas. Ta coatings were deposited at substrate temperature of 370-400 °C, reactor working pressures of 0.7-2 Ton, hydrogen carrier flow rate of 10-20 sccm, hydrogen reactant flow rates of 500 sccm, and plasma power ranging from 60 to 100W. Ta coatings were characterized with respect to their chemical, structural, and morphological properties by Auger electron spectroscopy (AES), x-ray diffraction (XRD), atomic force microscopy (AFM), x-ray photoelectron spectroscopy (XPS), scanning …

Automatic Prediction Of Solar Flares And Super Geomagnetic Storms, Hui Song

Dissertations

Space weather is the response of our space environment to the constantly changing Sun. As the new technology advances, mankind has become more and more dependent on space system, satellite-based services. A geomagnetic storm, a disturbance in Earth's magnetosphere, may produce many harmful effects on Earth. Solar flares and Coronal Mass Ejections (CMEs) are believed to be the major causes of geomagnetic storms. Thus, establishing a real time forecasting method for them is very important in space weather study.

The topics covered in this dissertation are: the relationship between magnetic gradient and magnetic shear of solar active regions; the relationship …