DATE: Friday, March 14, 2014
TIME: 12:20 pm - 1:35 pm
LOCATION: 327 Campbell Hall
"Magnetic Resonance Spectroscopy of p-type Dopants in Wide Bandgap Semiconductors: GaN and ZnO"
Evan R. Glaser
Naval Research Laboratory
The quest to produce large hole concentrations (>1018 cm-3) with high carrier mobilities in epitaxial and bulk wide bandgap semiconductors GaN and ZnO has been of high scientific and technological interest throughout the past 20 years. The transport properties for several potential p-type dopants such as Mg and Be in GaN and Li, Na, and N impurities in ZnO have been investigated by many groups with varying degrees of success. In this presentation I will highlight our research at NRL using defect-sensitive magnetic resonance techniques (including electron paramagnetic resonance and optically-detected magnetic resonance) that provide many insights on the nature of the electronic states associated with, in particular, Mg impurities in GaN and N in ZnO. In addition, these studies reveal the presence of dopant-related and/or other defect complex centers that act as deep trap states and limit or significantly compromise the ability to achieve high hole densities in these materials.
WKU NOVA Center: Nondestructive Analysis Using the Large Chamber Scanning Electron Microscope
Dr. Edward Kintzel
Department of Physics
Western Kentucky University
The Western Kentucky University (WKU) Nondestructive Analysis (NOVA) Center has been established within the Commonwealth of Kentucky. The acquisition of the Large Chamber-Scanning Electron Microscope (LC-SEM) has positioned WKU as the only university in North America with an instrument of this type. As envisioned, the NOVA Center will be a national focal point for nondestructive measurements. The reach of this Center is to provide analytical services, by being the only educational institution within North America to offer non-destructive SEM analysis. Transdisciplinary studies will be presented that highlight the extensive suite of materials characterization techniques available at the WKU NOVA Center.