Collision of H and He ions with silicon: A time dependent density functional theory study

This study employs time-dependent density functional theory (TDDFT) to simulate the collision processes of hydrogen (H) and helium (He) ions (0.5–10 keV) with silicon along the < 100 > orientation. By comparing the differences in stopping power among particles with different charge states (e.g., proton, H, He, He²⁺) in the material, it is found that the projectile charge state and atomic number are key factors governing the energy dissipation of incident ions. Further analysis combining real-time charge-state tracking and force evolution elucidates the microscopic mechanisms of ions energy dissipation in the material. A comparison with SRIM simulation results confirms the critical role of atomic/electronic structure in the accurate calculation of stopping power. Based on the density of states (DOS) and differential charge density, we elucidate the characteristic evolution of electronic states and the charge transfer dynamics in collision systems. This research provides important theoretical support for a deeper understanding of ion collision dynamics and the precise construction of radiation damage models.