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

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61389021%3A_____%2F21%3A00546981" target="_blank" >RIV/61389021:_____/21:00546981 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/68378271:_____/21:00545281

Výsledek na webu

<a href="https://journals.aps.org/prb/abstract/10.1103/PhysRevB.103.224306" target="_blank" >https://journals.aps.org/prb/abstract/10.1103/PhysRevB.103.224306</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1103/PhysRevB.103.224306" target="_blank" >10.1103/PhysRevB.103.224306</a>

Jazyk výsledku

angličtina

Název v původním jazyce

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

Popis výsledku v původním jazyce

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.

Název v anglickém jazyce

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

Popis výsledku anglicky

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.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10305 - Fluids and plasma physics (including surface physics)

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2021

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Physical Review B

ISSN

2469-9950

e-ISSN

2469-9969

Svazek periodika

103

Číslo periodika v rámci svazku

22

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

13

Strana od-do

224306

Kód UT WoS článku

000662302600001

EID výsledku v databázi Scopus

2-s2.0-85108244408