scholarly journals Probing the Hydrogen Enhanced Near-Field Emission of ITO without a Vacuum-Gap

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Jacob L. Poole ◽  
Yang Yu ◽  
Paul R. Ohodnicki
Keyword(s):  
Author(s):  
D.A. Zanin ◽  
H. Cabrera ◽  
L.G. De Pietro ◽  
M. Pikulski ◽  
M. Goldmann ◽  
...  

Author(s):  
A. Chatziafratis ◽  
G. Fikioris ◽  
J. P. Xanthakis

The progress in field emission theory from its initial Fowler–Nordheim form is centred on the transmission coefficient. For the supply (of electrons) function one still uses the constant value due to a supply of plane-waves states. However, for emitting tips of apex radius of 1–5 nm this is highly questionable. To address this issue, we have solved the Schrödinger equation in a sharp paraboloidally shaped quantum box. The Schrödinger equation is separable in the rotationally parabolic coordinate system and we hence obtain the exact eigenstates of the system. Significant differences from the usual Cartesian geometry are obtained. (1) Both the normally incident and parallel electron fluxes are functions of the angle to the emitter axis and affect the emission angle. (2) The WKB approximation fails for this system. (3) The eigenfunctions of the nanoemitter form a continuum only in one dimension while complete discretization occurs in the other two directions. (4) The parallel electron velocity vanishes at the apex which may explain the recent spot-size measurements in near-field scanning electron microscopy. (5) Competing effects are found as the tip radius decreases to 1 nm: The electric field increases but the total supply function decreases so that possibly an optimum radius exists.


Author(s):  
S. Basu ◽  
B. J. Lee ◽  
Z. M. Zhang

This paper describes a theoretical investigation of near-field radiative heat transfer between doped silicon surfaces separated by a vacuum gap. Using an improved dielectric function model for heavily doped silicon, along with fluctuation-dissipation theorem, and dyadic Green’s function, the present authors calculated the energy transfer between the doped silicon surfaces near room temperature. The effects of doping level, polarization, and width of the vacuum gap on the overall radiative transfer were investigated. It was observed that increase in the doping concentration of the emitter does not necessarily enhance the energy transfer in the near field. The energy-streamline method was used to model the lateral shift of the energy pathway, which is the trace of the Poynting vectors in the vacuum gap. The analysis performed in this study may facilitate the understanding of near-field radiation for applications such as thermal management in nanoelectronics, energy conversion systems, and nanothermal manufacturing.


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