R. STANLEY WILLIAMS
Professor; BA, Rice University; MS and PhD, University of California, Berkeley; NSF Fellow; Alfred P. Sloan Fellow; Camille and Henry Dreyfus
Teacher-Scholar; Glenn T. Seaborg Research Award; Herbert Newby McCoy Award.
RESEARCH DESCRIPTION:
The work in our laboratories is motivated by the technological requirements for future optoelectronic materials and the excitement of exploring new
scientific frontiers. We prepare clean single-crystal surfaces under ultra-high-vacuum conditions and then by the technique of molecular beam epitaxy, chemical vapor deposition, or laser ablation grow one or more
ordered overlayers of different types of materials. The long-term goal of this research is to create new crystalline composites with unusual and useful optical and electronic properties, which are controlled by the chemical identity
of the layers and their physical dimensions (quantum size effects).
The thickness of the layers that are grown often approach atomic dimensions, and therefore surface-sensitive probes are required to characterize
their properties. We utilize a broad range of crystallographic and spectroscopic techniques: scanning tunneling microscopy, low-energy
electron diffraction, scanning electron microscopy, Auger and photoelectron spectroscopies, secondary-ion mass spectroscopy, and laser-excited photoluminescence with picosecond time resolution.
Each of these tools provides a few clues to help understand the structural electrical, and chemical nature of the materials we grow, and the
primary work in our group is organizing a wide range of data to form a coherent picture of the samples studied. Our studies span the discipline of physical chemistry: the kinetics of surface growth, the thermodynamics of
interface formation and aging, and the quantum mechanics of nanometer scale structures.
As an example of ongoing research see
Atomic Force Microscope (AFM) topographic maps of semiconductor CuCl
and the
Nanomanipulator
Project
KEY CONCEPTS AND WORDS:
Surface and Interface Chemistry: growth of crystalline thin films of
high-Tc superconductors; intermetallic compounds; semiconductors and
insulators; crystallographic and spectroscopic investigations of surfaces and interfaces; nanometer-scale thermochemistry and kinetics of solids.
Last Revision: 10/25/95 // mk
