Vasiliy V. Trofimov

Field Emission spectroscopy of silicon carbide: Natural modelling

This article discusses the problem of measurement of Field Emission Energy Distribution (FEED) from silicon carbide by the retarding potential method. A description of an natural experiment setting is presented as well as a model of its electrophysical system of field emission current differentiation by modulated retarding potential. It discusses problems of implementations of the measurement on a field emission array (FEA) 6H-SiC.

Field emission spectroscopy of SiC

Experimental set up for the natural experiment and measurement model are presented to obtain the feld emission energy distribution spectrum out of silicon carbide in case of the macro-sample having a macroscopic shape of a tip. The prototype of feld emission 6H - SiC monolithic cathode is proposed for spectroscopy measurements, and characterised by current-voltage dependence at macroscale interelectrode distance.

Technique for investigating the spatial structure of thin films at a nanolevel

A holographic microscope is intended for investigation and visual observation of nanoobjects that are thin metal films or macromolecules. A module providing for the experimental research of such objects has been designed and built. The optimal thickness of the metal films has been estimated. Software for processing the interference patterns with the aim of obtaining a holographic image of nanoobjects has been developed.

Studying the electrophysical parameters of a holographic microscope

In this work, the main parameters of a holographic microscope are studied with the aim of optimizing them. The optimum positions for the monochromatic electron-beam source with respect to the subject of research and for the screen detecting the interference pattern (the distance is 100 nm and 10 cm, respectively) are determined. The limiting thickness of the thin film of the subject of study (30 Å) at which the interference pattern can be observed is estimated. The main parameters of the coordinate-sensitive detector providing signal gain up to 105 at the output are calculated.

Peculiarities of the total energy distribution of field emission electrons from graphene-like structures

It is demonstrated that the field emission from graphene-like structures (GLSs) has a very low excitation threshold (about two orders of magnitude lower than that of metals and semiconductors). It is shown that the total energy distribution (TED) of field emission electrons from GLSs differs considerably from the spectra obtained for metals. The existence of two maxima of this distribution (spaced 0.7–1.7 eV apart), significant broadening of the energy distribution, and a shift of these maxima depending on the electric field intensity are reported. The resonance nature of low-threshold field emission from GLSs is confirmed.

Experimental study of the low threshold electron emission behavior from multi-layered graphene-like structures

The comprehensive study of the low threshold electron emission from multi-layered graphene-like structures (GLS) has been undertaken. The spectrum of emitted electrons from GLS has been obtained by retarding potential method. The state of the surface has been evaluated using scanning electron microscopy (SEM) and field emission microscopy (FEM). The peculiarities of the structure of experimental samples were analyzed by the methods of Raman spectroscopy and X-ray diffraction. It has been found that the maximum of the energy distribution is displaced 6.1–6.8 eV below the vacuum values. It has been observed that with the growth of the electric field the maximum of the energy distribution shifts to the region of low energies while the energy spectrum broadens up to 0.7–1.2 eV. Studies of the emitting surface by FEM and SEM allowed one to conclude that the surface is sufficiently smooth. The field enhancement factor due to the micro-roughness does not exceed 3–10 times.

Mathematical foundations of information processing methods dielectric spectroscopy of thin films

The system of real-time dielectric spectroscopy was elaborated. The mathematical model for determining the optical properties of thin films on a transparent substrate was developed. The study of the optical properties of thin films efficient emitters of interest in practical applications was performed.

Features of full energy distribution from graphene like structures by the retarding potential method

It was given the experimental results of study energy distribution of the field emitted electrons from graphene like structures by retarding potential method. It was presented the results of electron microscopy of the cathode surface and Raman spectroscopy investigated materials.

Study of the optimum conditions of a vacuum holographic microscope

The parameters of a kendroscope associated with the necessary position of the electron source and the object of research are optimized. The selection of thin layers of some metals suitable for visual observation of their structure and initial film growth is carried out.

Calculation of distribution of electron density on surface of thin films

Systems of monolayer films of graphene, porthyrin, copper and zinc phthalocyanine are investigated. For all systems equilibrium geometries are found, all structures are flat, except for a chlorine-replaced copper phthalocyanine. DFT modeling of the structure of thin films is performed as substantially promotion in interpretation of the results received by means of a holographic microscope.