Wafers

Wafers are thin, flat slices of semiconductor material used as the base for manufacturing electronic devices and solar cells. In most commercial solar panels, they are made from crystalline silicon.

Production begins with high-purity silicon, known as polysilicon, which is melted and formed into solid blocks called ingots. These ingots are cut into thin wafers, typically using diamond-wire saws. Manufacturers then process the wafers through steps such as surface texturing, doping, coating and the application of electrical contacts to create solar cells capable of converting sunlight into electricity. The cells are subsequently connected and assembled into solar modules.

Silicon wafers fall into two main categories:

Monocrystalline wafers: Cut from a single silicon crystal. They have a uniform crystal structure and dominate modern commercial solar manufacturing because they support high conversion efficiencies.
Multicrystalline wafers: Cut from silicon containing multiple crystal grains. These were widely used in earlier solar panels but have largely been displaced by monocrystalline products.

Wafer thickness, dimensions, purity and crystal quality affect cell performance, manufacturing yield and material consumption. Thinner wafers can reduce silicon use, but they require careful handling to limit breakage.

In the solar supply chain, wafers sit between ingot production and cell manufacturing. A wafer is an intermediate material: it must undergo further processing before it becomes a functioning solar cell.