Modeling and Simulation of Quantum Dots and and Other Nanostructure
Thursday, February 24, 2011
In microelectronic technology, there is a need to manufacture the next generation of smaller, faster, and efficient devices. However there are some fundamental limits mostly fabrication based that will prevent continues shrinkage of devices. The use of self-assembly process to manufacture ordered semiconductor nanostructures such as quantum dots, quantum molecules promises to be an inexpensive and effective route to overcome size scale limitations in current fabrication processes. In crystalline films these structures arise through competition among surface and bulk forces that result in instability. Instability may originate from a lattice misfit between film and substrate, from strong surface anisotropies or from kinetic surface fluxes. Producing such ordered nanostructure is still challenging. A fundamental understanding of the self-assembly process (nucleation, growth and coarsening) during epitaxial growth is necessary to achieve controlled quantum scale structures. We study the influence of anisotropic surface and strain energies as well as continuous mass deposition on heteroepitaxial thin film growth. There are different classical ways
to model these anisotropic energies; however, they have mathematical and physical limitations. This motivated us to develop new ways to model and simulate these energies. In particular, we develop and investigate two new phase-field models for strongly anisotropic surface energies.
Solmaz Torabi received her B.S. from the Sharif University of Technology (Tehran, Iran) in 2003, her M.S. from the University of Texas, Arlington, in 2005 and her Ph.D. from University of California, Irvine, in 2010, all in Materials Science and Engineering. Currently she is a postdoctoral researcher at Math Department in University of California, Irvine. Her research interests lie in the theoretical and computational aspects of Material Science especially multi-scale modeling with application to semiconductors. Currently, her research is focused on studying novel theoretical and computational approaches to implement anisotropic surface and elastic energies in epitaxial growth, their interactions, and their effect on the resulting morphologies. This work includes modeling and the development and implementation of new adaptive nonlinear multigrid finite difference methods to solve moving boundary problems related to thin film and crystal growth.
Host: S. Prudhomme