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0223U002179,
0121U109987
,
Physical bases of technologies of creation of electron-emitting surfaces with low work of an exit and negative electronic affinity
Horiachko Andrii M., Доктор фізико-математичних наук
12-02-2023
Taras Shevchenko National University of Kyiv
The object of research is nanoscale systems of Gd and Ce oxides on Si and Mo surfaces. The purpose of the work is to develop the physical foundations of the technology for the preparation of cathode surfaces with deposited layers of oxides of rare earth metals, which have a low work function, a high quantum yield, and a high coefficient of secondary electronic emission. Research methods – electronic spectroscopy, electron diffraction of electrons, scanning probe microscopy, analytical calculations, numerical calculations. The physical foundations of the technology for the production of electron-emitting surfaces by self-assembly in an electric field of a nanoscale relief in the form of nanowisters or nanofibers from a material with a large bandgap width have been created zones on a silicon or molybdenum substrate, including cerium and gadolinium oxides. A prototype was created for experimental measurements of autoelectron emission current from emitting surfaces and a test setup was built for manufacturing nanofibers from oxide materials by electrospinning and applying them to the substrate. Microwave adsorption by brominated carbon fibers was measured based on the standing wave technique. Based on these measurements, the potential shielding properties of these fiber coatings in various radio bands were evaluated. A consistent theory of field emission from nanostructured semiconductor SiC was constructed using of the created analytical model for the field amplification coefficient in the case of sufficiently "smoothed" protrusions, the surface of which is described by a Lorentzian-type curve. A simple theoretical model has been developed that relates the decrease in electron affinity of a semiconductor (or dielectric) to such parameters as the surface charge density localized on surface states or adsorbed atoms and the volume charge density in the space charge region, which together form a doubly charged layer on the surface.
Kolesnyk Oleg G.
Moiseienko Vladyslav A.
Strikha Maksym V.
Fedorchenko Mykola І.
2023-02-12
Updated: 2025-12-08
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