Simulation of Single Particle Displacement Damage in Si₁₋ₓGeₓ Alloys-Interaction of Primary Particles With the Material and Generation of the Damage Structure

Primary simulations of neutron interactions are performed on Si 1− x Ge x alloys with a Monte Carlo (MC) code using the binary collision approximation (BCA). Then, a statistical study of the collision cascades development in Si 0.8 Ge 0.2 , Si 0.7 Ge 0.3 , and Si 0.5 Ge 0.5 is carried out using molecular dynamics (MD), starting from both Si and Ge primary knock-on atoms (PKAs) of 1, 5, and 10 keV. The well-known Stillinger-Weber (SW) MD potential, which can be used to study Si, Ge, and Si 1− x Ge x , is coupled to the Ziegler-Biersack-Littmark (ZBL) universal potential to better describe the collisions between atoms. To account for the stopping power of the electrons, the two-temperature model (TTM) is combined with MD. Similar studies are performed on pure Si and pure Ge in order to be able to compare our Si-Ge alloys damaged structures with reference materials. Moreover, data obtained by TTM-MD on Si, Ge, and Si 1− x Ge x are compared with collision cascades statistical data from MC codes.