Dielectric Function and Magnetic Moment of Silicon Carbide Containing Silicon Vacancies

In this work, silicon carbide layers containing silicon vacancies are grown by the Method of Coordinated Substitution of Atoms (MCSA). The main idea of this fundamentally new method is that silicon vacancies are first created in silicon, which is much simpler, and only then is silicon converted into silicon carbide by chemical reaction with carbon monoxide. The dielectric function of silicon carbide containing silicon vacancies, grown on both n- and p-type silicon substrates, is measured for the first time. The density functional method in the spin-polarized approximation is used to calculate the dielectric function of silicon carbide containing silicon vacancies. It is shown that the influence of the magnetic moment of vacancies on the dielectric function is decisive. Qualitative correspondence of the computational model to the obtained experimental data is demonstrated. It is discovered that silicon vacancies make silicon carbide much less transparent. It is shown that the imaginary part of the dielectric function is described as a sum of oscillatory peaks in the form of the Gaussian functions. Vacancies lead, as a rule, to one or two additional peaks. According to the amplitude and position of the additional peaks, it is possible to qualitatively estimate the concentration of vacancies and their charge.