Engineering Commons^™

Chemical And Electronic Structure Of Surfaces And Interfaces In Cadmium Telluride Based Photovoltaic Devices, Douglas Arthur Duncan

UNLV Theses, Dissertations, Professional Papers, and Capstones

The surface and interface properties are of the upmost importance in the understanding, optimization, and application for photovoltaic devices. Often the chemical, electronic, and morphological properties of the films are empirically optimized, however when progress slows, a fundamental understanding of these properties can lead to breakthroughs. In this work, surfaces and interfaces of solar cell-relevant films are probed with a repertoire of X-ray analytical and microanalysis techniques including X-ray photoelectron (XPS), X-ray excited Auger electron (XAES), X-ray emission (XES) spectroscopies, and atomic force (AFM) and scanning electron (SEM) microscopies.

Silicon-based devices currently dominate the solar market, which is rather inflexible …

In Vacuo Fabrication And Electronic Structure Characterization Of Atomic Layer Deposition Thin Films, Michael Schaefer

USF Tampa Graduate Theses and Dissertations

Improvement of novel electronic devices is possible by tailor-designing the electronic structure at device interfaces. Common problems observed at interfaces are related to unwanted band alignment caused by the chemical diversity of interface partners, influencing device performance negatively. One way to address this problem is by introducing ultra-thin interfacial dipole layers, steering the band alignment in a desired direction. The requirements are strict in terms of thickness, conformity and low density of defects, making sophisticated deposition techniques necessary. Atomic layer deposition (ALD) with its Ångstrom-precise thickness control can fulfill those requirements.

The work presented here encompasses the implementation of an …

Investigation Of Lanthanide-Doped Anatase Tio2 Core-Shell Nanoparticles For Photocatalysis And Gas Sensing, Rezwanur Rahman

MSU Graduate Theses

Anatase TiO2 has been shown to be potential applications for photo-remediation of chemical waste as well as for photocatalytic splitting of water. The catalytic properties of TiO2 materials can be modified by doping with lanthanide (Ln) ions. In order to minimize the distortion and/or change of the structure of TiO2 nanoparticles, surface doping of anatase TiO2 nanoparticles (~ 14 nm) with several Ln ions (Nd3+, Gd3+, Eu3+, Yb3+) has been successfully made. X-ray diffraction (XRD) and Raman characterization shows that the anatase phase of treated nanoparticles is well preserved. Scanning electron microscopy (SEM) shows that the majority of the nanoparticles …