For the photovoltaic industry, the production of solar cells is inseparable from the heat treatment furnace, from the manufacture of silicon wafers, the use of monocrystalline silicon growth furnace, through the carbon arc welding (CAW), to reduce the oxygen of the silicon dioxide species, to obtain the fusion furnace, and then through the floating zone technology (FTZ) for purification. The crystals are then spun and formed into pure cylindrical ingots for the manufacture of monocrystalline silicon cells by the straight drawing (CZ) process.

The ingots are cut into wafers required for solar cells according to geometrical requirements. Geometrical and thickness inconsistencies and damaged wafers are removed through inspection and pre-treatment, and then cleaned with industrial soap to remove impurities such as metal residues from the surface.

Subsequently, the front surface of the silicon wafer or the surface of the wafer is textured by photolithography through random pyramid texturing technology or inverted pyramid texturing technology to reduce the reflection loss of incident light.

The surface particles, silicon oxide layer and metal residues are removed from the wafer by acid washing, hydrogen fluoride (HF) vapour and hydrogen chloride (HCI).

Subsequently, the wafer is treated by solid state diffusion or emitter diffusion, which also requires the use of our diffusion furnace, click for more information.

Once diffusion is complete the exposed edges are then treated by etching and edge isolation to remove the electrical paths around the wafer edges.

The wafer is then cleaned a second time to remove process residues from the previous etching, and then the surface is coated with an anti-radiation AR coating by chemical vapour deposition using silicon nitride or titanium nitride. This step requires the use of our pecvd furnace, click for more information on this.

After completing these steps, the dry metal paste is cured on the wafer by contact printing and clean, before being passed through our sintering furnace. The wafers are then cooled and are ready to become solar cells.