Atomistic Simulation Study of Dislocations and Grain Boundaries in Nanoscale Semiconductors

摘要

The atomistic and electronic structures of "grain boundaries" and "dislocations" in nanoscale semiconductors are studied using the O(N) generalized tight-binding molecular dynamics method. We compare the atomistic properties of nanocrystalline semiconductors containing "extended defects" with those of bulk-size materials. The atomic and electronic structures of misfit dislocations at semiconductor heterostructures including interface disorder are also investigated using the density-functional tight-binding method. The misfit dislocations both edge type 1/2 <110> (001) and 60°cdislocations in the semiconductor heterostructures like Ge/Si (001) are studied and the critical layer thickness h_c for the generation of misfit dislocations is determined.