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The proximity of the anode to a curved field electron emitter alters the electric field at the apex and its neighbourhood. A formula for the apex field enhancement factor, $\gamma_a(D)$, for generic smooth emitters is derived using the line…

Applied Physics · Physics 2022-01-06 Debabrata Biswas

Large area field electron emitters, typically consisting of several thousands of nanotips, pose a major challenge since numerical modeling requires enormous computational resources. We propose a hybrid approach where the local electrostatic…

Applied Physics · Physics 2022-01-06 Debabrata Biswas

It is well known that sufficiently strong electrostatic fields are able to change the morphology of Large Area Field Emitters (LAFEs). This phenomenon affects the electrostatic interactions between adjacent sites on a LAFE during field…

Mesoscale and Nanoscale Physics · Physics 2018-04-03 Edgar Marcelino , Thiago A. de Assis , Caio M. C. de Castilho

Electrostatic shielding is an important consideration for large area field emitters (LAFE) and results in a distribution of field enhancement factors even when the constituent emitters are identical. Ideally, the mean and variance together…

Applied Physics · Physics 2021-12-10 Rashbihari Rudra , Debabrata Biswas

Both single emitters and large area field emitters (LAFE) are generally characterized using the slope and intercept of a Murphy-Good (or Fowler-Nordheim) plot which are used to extract the field enhancement factor and the emission area.…

Applied Physics · Physics 2022-02-24 Debabrata Biswas

A recent analytical model for large area field emitters, based on the line charge model (LCM), provides a simple approximate formula for the field enhancement on hemi-ellipsoidal emitter tips in terms of the ratio of emitter height and…

Applied Physics · Physics 2022-01-06 Rashbihari Rudra , Debabrata Biswas

This paper improves understanding of electrostatic influences on apex field enhancement factors (AFEFs) for small field emitter arrays. Using the "floating sphere at emitter-plate potential" (FSEPP) model, it re-examines the electrostatics…

Mesoscale and Nanoscale Physics · Physics 2018-12-19 Richard G. Forbes

Experiments on field electron emission from single-tip nanoemitters have typically been carried out using a counter-electrode with a finite curvature radius $R$, positioned at a distance $d_{\rm{gap}}$ from the emitter's apex. The effects…

Mesoscale and Nanoscale Physics · Physics 2025-02-12 Thiago A. de Assis , Fernando F. Dalll'Agnol

A field in a homogeneous medium can be amplified or enhanced by inserting closely located perfectly conducting inclusions into the medium. In this paper precise quantitative estimates for such enhancement are derived when the given field is…

Analysis of PDEs · Mathematics 2019-09-10 Hyeonbae Kang , KiHyun Yun

We demonstrate that the electric field enhancement that occurs in a gap between two closely spaced nanostructures, such as metallic nanoparticles, is the result of a transverse electromagnetic waveguide mode. We derive an explicit…

Mesoscale and Nanoscale Physics · Physics 2015-05-19 Jeffrey M. McMahon , Stephen K. Gray , George C. Schatz

The field enhancement factor at the emitter tip and its variation in a close neighbourhood determines the emitter current in a Fowler-Nordheim like formulation. For an axially symmetric emitter with a smooth tip, it is shown that the…

Applied Physics · Physics 2018-01-30 Debabrata Biswas , Gaurav Singh , Shreya G. Sarkar , Raghwendra Kumar

We report on the application of Atomic Force Microscopy (AFM) for studying the Field Emission (FE) properties of a dense array of long and vertically quasi-aligned multi-walled carbon nanotubes grown by catalytic Chemical Vapor Deposition…

We theoretically investigate the dependence of the enhancement of optical near-fields at nanometric tips on the shape, size, and material of the tip. We confirm a strong dependence of the field enhancement factor on the radius of curvature.…

In this work we study the strong confinement effects on the electromagnetic response of metallic nanoparticles. We calculate the field enhancement factor for nanospheres of various radii by using optical constants obtained from both…

Mesoscale and Nanoscale Physics · Physics 2018-02-20 Mario Zapata-Herrera , Jefferson Flórez , Angela Camacho , Hanz Y. Ramirez

The extremely local electric field enhancement and light confinement is demonstrated in dielectric waveguide with corner and gap geometry. The numerical results reveal the local electric field enhancement in the vicinity of the apex of…

Optics · Physics 2014-07-29 Qijing Lu , Fang-Jie Shu , Chang-Ling Zou

We analytically study the spontaneous emission of a single optical dipole emitter in the vicinity of a plasmonic nanoshell, based on the Lorenz-Mie theory. We show that the fluorescence enhancement due to the coupling between optical…

A large area field emitter (LAFE) typically consists of several thousands of nanoscale emitting tips. These are difficult to simulate using purely numerical methods based on finite/boundary element or finite difference methods. We show here…

Applied Physics · Physics 2022-07-21 Debabrata Biswas , Rashbihari Rudra , Raghwendra Kumar

A field excited by an emitter can be enhanced due to presence of closely located inclusions. In this paper we consider such field enhancement when inclusions are disks of the same radii, and the emitter is of dipole type and located in the…

Analysis of PDEs · Mathematics 2018-11-06 Hyeonbae Kang , KiHyun Yun

Field emission from nano-structured emitters primarily takes place from the tips. Using recent results on the variation of enhancement factor around the apex (Biswas et al, Ultramicroscopy 185, 1-4 (2018)), analytical expressions for…

Applied Physics · Physics 2018-05-24 Debabrata Biswas

We fabricate AlGaN nanowires by molecular beam epitaxy and we investigate their field emission properties by means of an experimental setup using nano-manipulated tungsten tips as electrodes, inside a scanning electron microscope. The…

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