Condensed-Matter Theory


Mailing address:
Vanderbilt University
Dept. of Physics & Astronomy
Box 1807-B
Nashville, TN 37235

Ph. (615) 343-4321
Fax (615) 343-7697
E-mail:
pantelides@vanderbilt.edu



Sokrates T. Pantelides


Distinguished Professor of Physics and Engineering

William A. and Nancy F. McMinn Professor of Physics

Professor of Electrical Engineering
 

Research Associates :

Graduate Students:

 

  • Yevgeniy Puzyrev

  • Xiao Shen

  • Bin Wang

  • Blair Tuttle (Penn State- Behrend)

  • Mark Oxley (ORNL)

  • Micah Prange (ORNL)

  • Jun He (ORNL)

  • Jaekwang Lee (ORNL)

  • Tim Pennycook

  • Keith Warnick





Prof. Pantelides Assistant: Vicki Abernathy (615) 343-7389


About the research

Professor Pantelides joined the faculty at Vanderbilt as the first William A. and Nancy F. McMinn Professor of Physics in August 1994. His research activities in the past spanned the following areas:

- Electronic structure and properties of bulk crystals, crystalline surfaces, and point defects in crystals

In this area, the main emphasis was on point defects. Theoretical techniques were pioneered to describe quantitatively from first principles the electronic structure of point defects in semiconductors at the same level of sophistication that was then possible for bulk crystals and crystalline surfaces. Other areas of investigation were point defects and electron states at the Si-SiO2 interface, Auger life times of carriers in Si, excitonic effects in the optical spectra of metals, x-ray absorption and excitons in ionic insulators.

- Equilibrium atomic arrangements and atomic dynamics in crystalline semiconductors

First-principles computer calculations were pioneered for formation and migration energies of point defects in semiconductors that enabled quantitative studies of atomic diffusion and defect reactions. A number of technologically important problems were elucidated, such as the mechanisms of etching of Si by F ions, the mechanisms of self-diffusion and dopant diffusion in Si, the energetics, diffusion and complex formation of H in Si, the solubilities and doping limitations of impurities in II-VI compound semiconductors, etc.

- The structure, point defects and dynamics of amorphous silicon

This work was based on the recognition that there are in principle two intrinsic point defects in amorphous silicon, namely three*fold-coordinated and fivefold-coordinated Si atoms. The properties of the latter were studied for the first time and later confirmed by more sophisticated calculations. The consequences of the dynamics of these defects and hydrogen led to systematic explanations of many puzzling experimental observations in amorphous silicon.

- Mesoscopic dynamics in polycrystalline solids

Starting with the fundamental axioms of quantum mechanics and statistical mechanics a set of field equations were derived that describe quantitatively the dynamics of heterogeneous materials at intermediate or mesoscopic length scales. The laws of continuum mechanics are recovered from first principles. The equations contain elastoplasticity from first principles and allow systematic studies of the evolution of the microstructure. Initial implementations of the theory focused on void morphologies in polycrystalline aluminum under electromigration conditions and the calculation of creep rates in bicrystals.

Planned or already started research activities at Vanderbilt will relate to the above areas and expand in related areas. One of the problems currently being studied are the clustering of dopant impurities in Si and the mechanisms for dopant deactivation in heavily doped Si. Emphasis will be placed on the problem of infrared absorption by crystals and crystalline surfaces containing defects and other structures. The purpose will be to explore the possibility of using infrared radiation to steer reactions by exciting specific vibrational modes. This work will be in conjunction with experimental work by other faculty using the Vanderbilt Free Electron Laser Center.

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