Thermionic Field Emission Gun

1978 ◽  
Author(s):  
W. Hant
Keyword(s):  
Field Emission ◽  
Thermionic Field Emission

Thermionic FEEM, PEEM and I/V Measurements of N-Doped CVD Diamond Surfaces

2000 ◽  
Vol 621 ◽  
Author(s):  
F.A.M. Köck ◽  
J.M. Garguilo ◽  
B. Brown ◽  
R.J. Nemanich
Keyword(s):  
Gas Phase ◽  
Field Emission ◽  
Electron Emission ◽  
Low Temperatures ◽  
Diamond Films ◽  
Cvd Diamond ◽  
Exponential Dependence ◽  
Diamond Surfaces ◽  
Cold Cathodes ◽  
Thermionic Field Emission

ABSTRACTImaging of field emission and photoemission from diamond surfaces is accomplished with a high resolution photo-electron emission microscope (PEEM). Measurements obtained as a function of sample temperature up to 1000°C display thermionic field emission images (TFEEM). The system can also record the emission current versus applied voltage. N-doped diamond films have been produced by MPCVD with a N/C gas phase ratio of 48. The surfaces display uniform emission in PEEM at all temperatures. No FEEM images are detectable below 500°C. At ∼680°C the T-FEEM and PEEM images are nearly identical in intensity and uniformity. This is to be contrasted with other carbon based cold cathodes in which the emission is observed from only a low density of highly emitting sites. The I/V measurements obtained from the N-doped films in the T-FEEM configuration show a component that depends linearly on voltage at low fields. At higher fields, an approximately exponential dependence is observed. At low temperatures employed (<700°C), the results indicate a thermionic component to the emitted current.

scholarly journals Modified expressions of field and thermionic-field emission for Schottky barrier diodes in the reverse regime

2021 ◽  
Vol 24 (1) ◽  
pp. 16-21
Author(s):  
A. Latreche ◽  
Keyword(s):  
Schottky Barrier ◽  
Field Emission ◽  
Image Force ◽  
Theoretical Work ◽  
Schottky Barrier Diodes ◽  
Current Voltage ◽  
Thermionic Field Emission ◽  
Emission Models ◽  
Current Densities ◽  
Relationship Of

In this theoretical work, the author has modified the current-voltage relationship of the field and thermionic–field emission models developed by Padovani and Stratton for the Schottky barrier diodes in the reverse bias conditions with account of the image force correction. Considered in this approach has been the shape of Schottky barrier as trapezoidal. The obtained results show a good agreement between current densities calculated within the framework of these developed models and those calculated using the general model.

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