Study of dislocations in nanoscale semiconductors by ab initio molecular dynamics and lattice Green's function methods

The electronic and mechanical properties of the nanoscale materials are studied by using an ab initio molecular dynamics (TBMD) method and temperature dependent lattice Green's Function method. The core structures of dislocations in semiconductor crystallites composed of similar to 1000 atoms are calculated using the ab initio TB molecular dynamics method and compared with those in the corresponding bulk semiconductors. The core structures of both 30 degrees and 90 degrees partial dislocations in Si crystallites are found to be similar to those of the bulk Si crystals, but excess energies of the dislocations are of considerably smaller in the small semiconductor crystallites. We also investigate the mechanical (dislocation) properties of carbon related nanoscale materials, graphen in comparison with CNT, by using the temperature dependent Lattice Green's function method and we will show that the thermodynamic and mechanical properties of the nanoscale materials are quite different from those of the corresponding bulk materials. (c) 2005 WILEYNCH Verlag GmbH & Co. KGaA, Weinheim