DON L. WILLIAMSON

	Don Williamson Professor Emeritus Meyer Hall Rm. 325A Phone: 273-3837 email: dwilliam@mines.edu
Professor. BS Lamar University; MS, PhD University of Washington.

Research Interests

My research continues at a modest level in my retirement. Itis centered around the use of three techniques to study the nanostructure of materials: Mossbauer spectroscopy, x-ray diffraction, and small-angle scattering. The first of these is a specialized method that involves nuclear gamma-ray resonance, which provides such ultra-high resolution that atomic-scale structural, magnetic, and electronic information can be derived for certain types of solids. X-ray diffraction is a common and powerful method for the determination of crystal structure of any type of material. A much less common technique is small-angle scattering of x-rays (SAXS), and it provides a picture of the degree of inhomogeneity on a scale from 1 to about 30 nanometers.

One research problem currently being addressed in my laboratory is the study of amorphous and semiconductors that are being developed for application as thin-film solar cells. The deposition of thin-film materials such as amorphous silicon and silicon-germanium alloys can lead to inhomogeneities such as nanovoids and columnar-like structures that may be detrimental to device performance. With SAXS we can "see" such features and provide detailed information on their size, shape, and density. We are learning which features are affecting the opto-electronic properties and how they can be controlled or eliminated by optimization of the film deposition conditions.

 Last Modified: November 28, 2005
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