Impact of Electronic Energy Dissipation on Primary Radiation Damage Formation in Silicon

Abstract

In this work, we investigate the role of ion-electron coupling in simulations of radiation damage formation in silicon using molecular dynamics simulations within a two-temperature model. We explore predictions of a threshold-free approach to the coupling that accounts for both the electronic stopping and electron-phonon coupling using a local electron density-based formalism. We compare two different coupling functions across a range of primary knock-on atom energies using two interatomic potentials. Our results demonstrate that the functional form of the ion-electron coupling plays a critical role in determining defect production efficiency, clustering, and recombination, and must therefore be carefully considered for accurate modeling of radiation damage formation. Furthermore, we find that the impact of the coupling in particular on the recombination of defects during the cooling phase of the cascade depends on the choice of interatomic potential, emphasizing the importance of physically grounded descriptions for both electronic effects and atom-atom interactions for reliable radiation damage predictions.