4.6 Article

Electron cascades and secondary electron emission in graphene under energetic ion irradiation

期刊

PHYSICAL REVIEW B
卷 103, 期 22, 页码 -

出版社

AMER PHYSICAL SOC
DOI: 10.1103/PhysRevB.103.224306

关键词

-

资金

  1. MATRENA doctoral program
  2. COST (European Cooperation in Science and Technology [CA17126]
  3. National Science Foundation [OAC-1740219, OCI-0725070, ACI-1238993]
  4. CERN K-contract [47207461]
  5. Czechia Ministry of Education, Youth and Sports, Czechia Republic [LTT17015, EF16_013/0001552]
  6. IAEA [F11020 CRP]
  7. state of Illinois
  8. DOE Office of Science User Facility [DE-AC02-06CH11357]
  9. University of Illinois at Urbana-Champaign

向作者/读者索取更多资源

This study demonstrates that under high-energy ion impact, electronic excitation in graphene can result in secondary electron emission, leading to a decrease in energy within the graphene layer. The probability of electron capture decreases rapidly with increasing ion velocity, with secondary electron emission dominating in the high-velocity regime.
Highly energetic ions traversing a two-dimensional material such as graphene produce strong electronic excitations. Electrons excited to energy states above the work function can give rise to secondary electron emission, reducing the amount of energy that remains in graphene after the ion impact. Electrons can be either emitted (kinetic energy transfer) or captured by the passing ion (potential energy transfer). To elucidate this behavior that is absent in three-dimensional materials, we simulate the electron dynamics in graphene during the first femtoseconds after ion impact. We employ two conceptually different computational methods: a Monte Carlo (MC)-based one, where electrons are treated as classical particles, and time-dependent density functional theory (TDDFT), where electrons are described quantum mechanically. We observe that the linear dependence of electron emission on deposited energy, emerging from MC simulations, becomes sublinear and closer to the TDDFT data when the electrostatic interactions of emitted electrons with graphene are taken into account via complementary particle-in-cell simulations. Our TDDFT simulations show that the probability for electron capture decreases rapidly with increasing ion velocity, whereas secondary electron emission dominates in the high-velocity regime. We estimate that these processes reduce the amount of energy deposited in the graphene layer by 15%-65%, depending on the ion and its velocity. This finding clearly shows that electron emission must be taken into consideration when modeling damage production in two-dimensional materials under ion irradiation.

作者

我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。

评论

主要评分

4.6
评分不足

次要评分

新颖性
-
重要性
-
科学严谨性
-
评价这篇论文

推荐

暂无数据
暂无数据