Growth of monocrystalline silicon in microgravity

Abstract

Solar batteries work on the basis of special modules - photocells that capture solar energy and convert it into electric current with the help of semiconductor devices. Photocells are a solar panel made from homogeneous monocrystalline silicon, which has not only high quality, but also high performance.
A solar panel is able to work at very low temperatures, in a small number of places, and at the same time its effectiveness does not disappear. The maximum duration of its use reaches 30 years.
Under terrestrial conditions, the growing of monocrystalline silicon is carried out by the Czochralski method, in which, when the seed comes into contact with the surface of the silicon melt, the atoms of which, in contact with the seed, lose energy and freeze, which leads to the growth of a silicon single crystal.
Under terrestrial conditions, gravitational forces create a strong thermo gravitational unsteady convection, which leads to instability of the growth parameters of monocrystalline silicon and limits the possibility of obtaining monocrystalline silicon with a high degree of uniformity.
The first results of growing monocrystalline silicon under microgravity conditions, where strong thermo gravitational unsteady convection disappears in the absence of gravity, showed the fundamental possibility of obtaining more perfect monocrystalline silicon.
However, under microgravity conditions in silicon melts, new opportunities for non-gravitational convective processes appear - Marangoni convection, as well as (in the presence of residual gravity) small thermo gravitational processes with a decrease in the level of gravity, which leads to the problem of obtaining homogeneous monocrystalline crystals.
The article presents the developed method for homogeneous monocrystalline silicon growing in microgravity by eliminating the arising non-gravitational convective processes by using controlled vertical vibration in a pre-calculated mode of the vibroturbulization process for mixing the internal components of the silicon melt in the process of growing homogeneous monocrystalline silicon by the Czochralski method in microgravity.
Keywords: monocrystalline silicon growth; monocrystalline silicon solar panel; Czochralski method; conditions of microgravity; vibroturbulization process.