>>10836393They use silicon from sand. That sand should have high silicon concentration. The silicon from the sand must be cleared from other materials.
Then they create two types of silicon.
N-type: They add phosporus to silicon.
P-type: They add boron to silicon.
To create a solar panel they put a thin N-type layer on top of a P-type layer.
https://www.youtube.com/watch?v=L_q6LRgKpTw 
