Jump to main content
Jump to site search

Issue 22, 2018
Previous Article Next Article

Observation of dynamical crater-shaped charge distribution in the space–time imaging of monolayer graphene

Author affiliations

Abstract

A better understanding of charge carrier dynamics in graphene is key to improvement of its electronic performance. Here, we present direct space–time visualization of carrier relaxation and diffusion in monolayer graphene using time-resolved scanning electron microscopy techniques. We observed striking fluence-dependent dynamic images, changing from a Gaussian shape to a novel crater-shaped pattern with increasing laser fluence. Such direct observation of dynamic changes in spatial charge distribution is not readily available from the conventional spectroscopic approaches, which reflect essentially overall effective carrier temperature and density. According to our analysis, for this crater-shaped carrier density to occur in aggregated electron–hole pairs in the high fluence regime there exists an unconventional Auger-assisted carrier recombination process to provide effective relaxation channels, most likely involving emission of optical phonons and plasmons, which is dynamically accessible due to a strong temporal overlap among them. The presented model allows us to successfully account for these unexpected phenomena and to quantitatively analyze the observed spatiotemporal behavior.

Graphical abstract: Observation of dynamical crater-shaped charge distribution in the space–time imaging of monolayer graphene

Back to tab navigation

Supplementary files

Publication details

The article was received on 28 Jan 2018, accepted on 12 Apr 2018 and first published on 13 Apr 2018


Article type: Communication
DOI: 10.1039/C8NR00789F
Citation: Nanoscale, 2018,10, 10343-10350
  •   Request permissions

    Observation of dynamical crater-shaped charge distribution in the space–time imaging of monolayer graphene

    J. Cho, J. Tang, T. Y. Hwang and A. H. Zewail, Nanoscale, 2018, 10, 10343
    DOI: 10.1039/C8NR00789F

Search articles by author

Spotlight

Advertisements