Modified Monte Carlo method for study of electron transport in degenerate electron gas in the presence of electron–electron interactions, application to graphene

Borowik, Piotr; Thobel, Jean-Luc; Adamowicz, Ludwik

doi:10.1016/j.jcp.2017.04.011

Cited by 13 publications

(8 citation statements)

References 52 publications

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“…These nonequilibrium hot electrons therefore go through different scattering mechanisms where they lose energy and thermalize. The most prominent scattering mechanisms in graphene are: (1) electron-electron (e-e) scattering, (2) optical phonon (OP) scattering, and (3) supercollision acoustic phonon (SC) scattering [12,[21][22][23][24][25][26][27][28]. While e-e scattering allows the hot electrons to elastically redistribute their excess energy among the "cold" electrons in the Fermi sea, both OP and SC scattering cause them to lose energy to the lattice.…”

Section: Hot Electron Emission Mechanism In Graphenementioning

confidence: 99%

Performance Limits of Graphene Hot Electron Emission Photoemitters

et al. 2020

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Hot electron emission from waveguide integrated graphene has been recently shown to occur at optical power densities multiple orders of magnitude lower than metal tips excited by subworkfunction photons. However, the experimentally observed electron emission currents were small, limiting the practical uses of such a mechanism. Here, we explore the performance limits of hot electron emission in graphene through experimentally calibrated simulations. Two regimes of non-equilibrium emission in graphene are identified, (i) single particle hot electron emission, where an electron is excited by a photon, and is emitted before losing significant energy through scattering, and (ii) ensemble hot electron emission, where the photon source causes nonequilibrium heating of the electron population beyond the electron lattice temperature. It is shown that through appropriate selection of photon energy, optical power density, and applied electric field hot electron emission can be used to create ultra-high current electron emitters with ultra-fast temporal responses in both the single particle and ensemble heating regimes. These results suggest that through appropriate design, hot electron emitters may overcome the limitations of thermionic and field emitters.

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Section: Hot Electron Emission Mechanism In Graphenementioning

confidence: 99%

Performance Limits of Graphene Hot Electron Emission Photoemitters

et al. 2020

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“…In addition, the highly random CuO nanoblade structures lead to more scattering and further degrades the image quality. To demonstrate the degradation due to the trench and nanoblade structures, we performed Monte Carlo (MC) simulation of the electron microscope images, [34][35][36][37][38] where the open-source model (Casino v3.3) developed by Drouin et al was used. [36] To understand the electron-substrate interaction, we separate out the effect of the electron-gas interaction, that is, we simulate at 0 Pa.…”

Section: Doi: 101002/advs202001268mentioning

confidence: 99%

Quasi‐Newtonian Environmental Scanning Electron Microscopy (QN‐ESEM) for Monitoring Material Dynamics in High‐Pressure Gaseous Environments

Zhu

Zhang

et al. 2020

Advanced Science

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Environmental scanning electron microscopy (ESEM) is a powerful technique that enables imaging of diverse specimens (e.g., biomaterials, chemical materials, nanomaterials) in a hydrated or native state while simultaneously maintaining micro-to-nanoscale resolution. However, it is difficult to achieve high signal-to-noise and artifact-free secondary electron images in a high-pressure gaseous environment due to the intensive electron-gas collisions. In addition, nanotextured substrates can mask the signal from a weakly scattering sample. These drawbacks limit the study of material dynamics under extreme conditions and correspondingly our understanding in many fields. In this work, an imaging framework called Quasi-Newtonian ESEM is proposed, which introduces the concepts of quasi-force and quasi-work by referencing the scattering force in light-matter interactions, to break these barriers without any hardware changes. It is shown that quasi-force is a more fundamental quantity that has a more significant connection with the sample morphology than intensity in the strongly scattering regime. Experimental and theoretical studies on the dynamics of droplet condensation in a high-pressure environment (up to 2500 Pa) successfully demonstrate the effectiveness and robustness of the framework and that the overwhelmed signal of interest in ESEM images can be reconstructed through information stored in the time domain, i.e., frames captured at different moments.

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“…However, the proposed formulas of e-e scattering rates account for the exchange effect without considering the multi-valley nature of electron transport in graphene. Such a method has been used by several authors [2,13,16,21,[25][26][27][28][29]. It should be also noted that this approach is suitable for spatially homogeneous systems, as it is assumed here.…”

Section: Introductionmentioning

confidence: 99%

Monte Carlo study of electron relaxation in graphene with spin polarized, degenerate electron gas in presence of electron-electron scattering

Borowik¹,

Thobel²,

Adamowicz³

2017

Semicond. Sci. Technol.

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The Monte Carlo simulation method is applied to study the relaxation of excited electrons in monolayer graphene. The presence of spin polarized background electrons population, with density corresponding to highly degenerate conditions is assumed. Formulas of electron-electron scattering rates, which properly account for electrons presence in two energetically degenerate, inequivalent valleys in this material are presented. The electron relaxation process can be divided into two phases: thermalization and cooling, which can be clearly distinguished when examining the standard deviation of electron energy distribution. The influence of the exchange effect in interactions between electrons with parallel spins is shown to be important only in transient conditions, especially during the thermalization phase.

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Modified Monte Carlo method for study of electron transport in degenerate electron gas in the presence of electron–electron interactions, application to graphene

Cited by 13 publications

References 52 publications

Performance Limits of Graphene Hot Electron Emission Photoemitters

Performance Limits of Graphene Hot Electron Emission Photoemitters

Quasi‐Newtonian Environmental Scanning Electron Microscopy (QN‐ESEM) for Monitoring Material Dynamics in High‐Pressure Gaseous Environments

Monte Carlo study of electron relaxation in graphene with spin polarized, degenerate electron gas in presence of electron-electron scattering

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