Resonant tunneling field emission of Si sponge-like structures

ABSTRACTNovel heterostructured cold cathodes made of nanoseeded diamond and cathodic arc process grown nanocluster carbon films, were studied. The nanocrystalline diamond with varying diamond concentration was first coated on to the substrate. The nanocluster carbon films were then deposited on the nanoseeded diamond coated substrates using the cathodic arc process at room temperature. The resultant heterostructured microcathodes were observed to exhibit electron emission currents of 1μA/cm2 at low fields of 1.2 - 5 V/μm. Further some of the samples seem to exhibit I-V characteristics with a negative differential resistance region at room temperature conditions. This negative differential resistance or the resonant tunneling behaviour was observed to be dependent on the nanoseeded diamond concentration.

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COOLING BY INVERSE NOTTINGHAM EFFECT WITH RESONANT TUNNELING

International Journal of High Speed Electronics and Systems ◽

10.1142/s0129156402001939 ◽

2002 ◽

Vol 12 (04) ◽

pp. 1083-1100 ◽

Cited By ~ 3

Author(s):

Y. YU ◽

R. F. GREENE ◽

R. TSU

Keyword(s):

Work Function ◽

Field Emission ◽

High Field ◽

Resonant Tunneling ◽

Cold Cathode ◽

Current Crowding ◽

Double Barrier ◽

Vacuum Electronics ◽

Barrier Heights ◽

Double Barrier Resonant Tunneling

The Inverse Nottingham Effect (INE) cooling involves emission of electrons above the Fermi level into the vacuum. Our scheme involves the use of a Double Barrier Resonant Tunneling (DBRT) section positioned between the surface and the vacuum for a much increased emission, and to provide energy selectivity for assuring cooling, without surface structuring such as tips and ridges leading to current crowding and additional heating. Unlike resonant tunneling from contact-to-contact, where barrier heights and thicknesses are controlled by the choice of heterojunctions, the work function at the surface dictates the barrier height for tunneling into the vacuum. The calculated field emission via resonant tunneling gives at least two orders of magnitude greater than without resonance, however, without work function lowering, the large gain happens at fairly high field. The use of resonance to enhance cooling by INE results in an important byproduct, an efficient cold-cathode field emitter for vacuum electronics.

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Theoretical analysis of 1D resonant tunneling behavior in ion-enhanced cold field and thermo-field emission

Journal of Applied Physics ◽

10.1063/1.4971263 ◽

2016 ◽

Vol 120 (21) ◽

pp. 213301 ◽

Cited By ~ 7

Author(s):

Xi Tan ◽

Paul Rumbach ◽

Nathaniel Griggs ◽

Kevin L. Jensen ◽

David B. Go

Keyword(s):

Theoretical Analysis ◽

Field Emission ◽

Resonant Tunneling ◽

Tunneling Behavior

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Observation of Phase Contrast Images in STEM and CTEM Modes by Using 100 kV Field Emission Electron Gun

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100051967 ◽

1974 ◽

Vol 32 ◽

pp. 390-391

Author(s):

Y. Harada ◽

T. Goto ◽

H. Koike ◽

T. Someya

Keyword(s):

Field Emission ◽

Phase Contrast ◽

Image Formation ◽

Fresnel Diffraction ◽

Experimental Results ◽

Electron Gun ◽

Scanning Microscopy ◽

Emission Electron ◽

Lattice Images

Since phase contrasts of STEM images, that is, Fresnel diffraction fringes or lattice images, manifest themselves in field emission scanning microscopy, the mechanism for image formation in the STEM mode has been investigated and compared with that in CTEM mode, resulting in the theory of reciprocity. It reveals that contrast in STEM images exhibits the same properties as contrast in CTEM images. However, it appears that the validity of the reciprocity theory, especially on the details of phase contrast, has not yet been fully proven by the experiments. In this work, we shall investigate the phase contrast images obtained in both the STEM and CTEM modes of a field emission microscope (100kV), and evaluate the validity of the reciprocity theory by comparing the experimental results.

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A New Image Processing Technique for STEM

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100052171 ◽

1974 ◽

Vol 32 ◽

pp. 432-433

Author(s):

Yasushi Kokubo ◽

Hirotami Koike ◽

Teruo Someya

Keyword(s):

Electron Microscopy ◽

Image Processing ◽

Scanning Electron Microscopy ◽

Elastic Scattering ◽

Field Emission ◽

Processing Technique ◽

Image Processing Technique ◽

Energy Analyzer ◽

Scanning Microscope ◽

Scanning Electron

One of the advantages of scanning electron microscopy is the capability for processing the image contrast, i.e., the image processing technique. Crewe et al were the first to apply this technique to a field emission scanning microscope and show images of individual atoms. They obtained a contrast which depended exclusively on the atomic numbers of specimen elements (Zcontrast), by displaying the images treated with the intensity ratio of elastically scattered to inelastically scattered electrons. The elastic scattering electrons were extracted by a solid detector and inelastic scattering electrons by an energy analyzer. We noted, however, that there is a possibility of the same contrast being obtained only by using an annular-type solid detector consisting of multiple concentric detector elements.

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Observation of Atom Rows in Thorium Pyromellitate Using a Field Emission STEM

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010007802x ◽

1977 ◽

Vol 35 ◽

pp. 80-81

Author(s):

H. Todokoro ◽

S. Nomura ◽

T. Komoda

Keyword(s):

Field Emission ◽

Amorphous Carbon ◽

Carbon Film ◽

Dark Field Image ◽

Dark Field ◽

Amorphous Carbon Film ◽

Atomic Size ◽

Wide Range ◽

A Chain

It is interesting to observe polymers at atomic size resolution. Some works have been reported for thorium pyromellitate by using a STEM (1), or a CTEM (2,3). The results showed that this polymer forms a chain in which thorium atoms are arranged. However, the distance between adjacent thorium atoms varies over a wide range (0.4-1.3nm) according to the different authors.The present authors have also observed thorium pyromellitate specimens by means of a field emission STEM, described in reference 4. The specimen was prepared by placing a drop of thorium pyromellitate in 10-3 CH3OH solution onto an amorphous carbon film about 2nm thick. The dark field image is shown in Fig. 1A. Thorium atoms are clearly observed as regular atom rows having a spacing of 0.85nm. This lattice gradually deteriorated by successive observations. The image changed to granular structures, as shown in Fig. 1B, which was taken after four scanning frames.

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