The article describes the results of the study of the microstructure and some electrophysical properties of silicon obtained by re-melting in a solar oven. It was found that the granularity of polycrystalline silicon consists of Si atoms with a size of 10-15 µm, the roughness of its surface. Decrease in speci c resistance at T≤600 K, increase in concentration of ionized input atoms and concentration of charge carriers, the position at Т∼600 ÷ 700 K is based on the decrease in the free path of the charge carriers as a result of thermal vibrations of the crystal lattice, the situation at T ≥ 700 K K was explained by the emergence of new recombination centers speci c to localized traps. Polycrystalline silicon heated by sunlight does not create a barrier effect of traps localized in the grain boundary regions from polycrystalline silicon obtained by other methods. This can expand the possibilities of creating highly e cient semiconductor devices, solar cells, thermoelectric materials for micro-and nanoelectronics, photovoltaics.