Silicon with structured oxygen doping, its production and use

摘要

Silicon and a process for producing silicon having a total oxygen content of 8x1017 atoms/cm3 to 1x1019 atoms/cm3 and a dislocation density of 1x105 cm-2 to 5x107 cm-2. The silicon has at least 25% of the oxygen contained in the form of silicon/oxygen precipitations that are concentrated in the area of the grain boundaries and dislocations. The process involves molten silicon being in contact with silicon monoxide and/or silicon dioxide therefore becoming saturated with oxygen, and/or the molten silicon is treated with an oxygen-containing gas before or during the crystallization. The dislocation density is set by means of the cooling rate of the silicon. The silicon finds use in film-casting or film drawing processes and in photovoltaics.