High-efficiency polycrystalline ingots improve the photoelectric conversion efficiency of solar cells

Recently, the photovoltaic industry has introduced a high-efficiency polycrystalline ingot casting technology that can reduce dislocations and other defects in crystals to improve the photoelectric conversion efficiency
of solar cells.

Ingot furnace is a device
that directly melts silicon at high temperature and condenses it through directional cooling to form silicon ingots with crystal direction.
After the silicon is completely melted by heating, the heat released when the silicon crystallizes is radiated to the inner wall of the lower furnace cavity through the directional solidification block, so that a vertical temperature gradient is formed in the polysilicon
.
This temperature gradient causes the silica inside the crucible to solidify from the bottom and grow
from the bottom of the melt to the top.
After the silicon solidifies, the silicon ingots are annealed and cooled before being baked
.
The optimization of the structure plays an important role
in improving the efficiency of the silicon ingot of the ingot.
Through the optimization of the thermal field temperature and the refinement of the grain, the nucleation of the crystal in the early stage is controlled, and the crystallization speed and subcooling degree are stabilized during the crystallization process, which improves the birthrate of the silicon crystal, reduces the internal defects of the silicon crystal, and improves the efficiency
of the solar cell.
It is reported that using ordinary cell production processes, high-efficiency multicrystalline silicon wafers can achieve a conversion efficiency of more than 17.
3%, and now it can reach up to about
18%.