Investigations of impurity gettering in multicrystalline silicon

The processes of gettering the recombination-active impurities in multicrystalline silicon were investigated using methods of mass spectrometry of neutral atoms with the depth profile analysis and spectroscopy of a surface photovoltage (permitting to determine the diffusion length of non-equilibrium charge carriers). Getters formed by a silicon layer with a developed internal surface, and also combined getter (the mentioned layer covered with a thin film of aluminum) were used. It was shown that the efficiency of gettering depends on annealing temperature and character of Al depth distribution that, in turn, depends on the regimes of structurally modified silicon layer formation. The models of gettering that enabled us to explain obtained results are considered

Detection statistics of the RadioAstron AGN survey

The largest Key Science Program of the RadioAstron space VLBI mission is a survey of active galactic nuclei (AGN). The main goal of the survey is to measure and study the brightness of AGN cores in order to better understand the physics of their emission while taking interstellar scattering into consideration. In this paper we present detection statistics for observations on ground-space baselines of a complete sample of radio-strong AGN at the wavelengths of 18, 6, and 1.3 cm. Two-thirds of them are indeed detected by RadioAstron and are found to contain extremely compact, tens to hundreds of μas structures within their cores.Peer reviewe