Anomalous Stopping and Charge Transfer in Proton-Irradiated Graphene

We use first-principles calculations to uncover and explain a new type of anomalous low-velocity stopping effect in proton-irradiated graphene. We attribute a shoulder feature that occurs exclusively for channeling protons to enhanced electron capture from sigma- and and pi-orbitals. Our analysis of electron emission indicates that backward emission is more sensitive to proton trajectory than forward emission and could thus produce higher contrast images in ion microscopy. For slow protons, we observe a steep drop in emission, consistent with predictions from analytical models.

Automated summary

Using first-principles calculations, the study uncovers and explains a new type of anomalous low-velocity stopping effect in proton-irradiated graphene, attributing it to enhanced electron capture from sigma- and pi-orbitals. The analysis of electron emission suggests that backward emission is more sensitive to proton trajectory, potentially leading to higher contrast images in ion microscopy. For slow protons, a steep drop in emission is observed, consistent with predictions from analytical models.