Photovoltaic industry. Annealing of a polycrystalline silicon wafer in an infrared furnace. The silicon wafers are being made into photovoltaic cells. Photovoltaic cells, the basic components of solar panels, contain silicon, a semiconductor material that can absorb energy from sunlight and convert it into an electrical current. Stages in the manufacturing process include thermal deposition, acid cleaning, infrared annealing, electrode addition, and testing and assembly into solar panel modules.