Authors: C. Lang, D. Nguyen-Manh and D.J.H. Cockayne
Affilation: University of Oxford, United Kingdom
Pages: 652 - 655
Keywords: atomistic modelling, molecular static relaxations, quantum dots, non-uniform alloying
We have obtained for the first time quantitative data about the energetics of alloyed Ge/Si Quantum Dots (QDs) from atomistic simulations which take into account the non-uniformity of the alloying profile. With the algorithm we developed we have been able to predict realistic alloying profiles. From the results of the atomistic simulations a simple analytical model for the energetics has been derived and we show that with the help of this model we can explain and determine accurately the variation of the shape transformation from the pyramid to the dome shape with the average composition. We also discuss the impact of the surface reconstruction on the energetics and compare results for the strain energy in this system obtained from finite element analysis and atomistic simulations.