Some Electrophysical Properties of Polycrystalline Silicon Obtained in a Solar Oven

Abstract

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. It is shown that at T ≤ 600 K the concentration of charge carriers increases due to an increase in the concentration of ionized impurity atoms, which, in turn, leads to a decrease in the resistivity of polycrystalline silicon. The position at T ~ 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 was explained by the emergence of new recombination centers specific 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 efficient semiconductor devices, solar cells, thermoelectric materials for micro- and nanoelectronics, photovoltaics.