Electronic stopping power under channeling conditions for slow ions in Ge using first principles

Abstract

The electronic stopping power for low-velocity ions (including protons and $\ensuremath{\alpha}$ particles) in the semiconductor Ge is investigated with the aid of time-dependent density functional theory based on Ehrenfest dynamics. The purpose of this study is to further learn about the energy loss mechanisms of the slow ions. When the projectile ions pass through the crystal film along the $\ensuremath{\langle}100\ensuremath{\rangle}, \ensuremath{\langle}110\ensuremath{\rangle}$, and $\ensuremath{\langle}111\ensuremath{\rangle}$ channels, we analyze the channeling effect of the electronic stopping power in detail by investigating the channeling electronic density, the stopping force, and the trapped electrons. Our results are in good agreement with the available experimental data and the other theoretical calculations, which demonstrate that this approach is able to reasonably describe the electronic stopping power. Furthermore, these results can act as the reference data for the ion-beam irradiation of Ge in the low-energy regime.