Mechanical and electronic properties of semiconductor nanocrystalline tetrapods

INOR 485

Joshua Schrier, jschrier@lbl.gov, Byounghak Lee, and Lin-Wang Wang, lwwang@lbl.gov. Computational Research Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Mailstop 50F-1650, Berkeley, CA 94720
It has recently become possible to study the mechanical and electronic properties of individual nanocrystalline tetrapod structures undergoing directional forces due to atomic force microscopy. In this talk, I will discuss our work on computational modeling combining classical mechanical simulation and large scale pseudopotential planewave density functional theory calculations to describe the electronic properties. By combining these approaches, we elucidate the nature of the nanocrystal-surface interactions via its role on the nanocrystal deformation forces and the effects of mechanical deformation on the band edge wavefunction properties. We find that the symmetry and degeneracy of the band-edge states can be controlled by varying the force applied by the AFM tip, thus offering a way to control the spatial localizations and symmetries of these states in a reversible manner.

This work was supported by the U. S. Department of Energy under Contract No. DE-AC03-76SF00098.