Production technology

The basis of silicon wafers production is growing of multicrystalline ingots from the liquid solar-grade silicon (SOG) (which is delivered by "MC "KazSilicon") with the help of vertically direct crystallization. Crystallization of solar silicon is underway in quartz crucibles in the furnaces with controlled thermal gradient and neutral gas purging.

Technological process of silicon wafers production from multicrystalline ingots includes the following main steps:

-       cutting ingots into bricks;

-       bricks quality control;

-       bricks cropping;

-       grinding;

-       chamfering;

-       gluing of prepared bricks onto glass substrates;

-       sawing bricks into wafers;

-       cleaning of wafers;

-       wafers separation;

-       wafers quality sorting.

During photovoltaic cells production the silicon wafers convert into solar cells (photocells).

The process of photovoltaic cells production includes several consecutive steps:

˗           texturing and chemical treatment of wafer surface,

˗          formation of base-emitter p-n junction,

˗           phosphosilicate glass removal and p-n junction isolation,

˗           deposition of antireflective coating,

˗           contact metallization,

˗           testing and sorting of final products.

 Then photovoltaic cells should be sent to "Astana Solar" LLT to be assembled into solar panels (modules).