The basic element in solar modules
The wafers are further processed to solar cells in the third production step. They form the basic element of the resulting solar modules. The cells already possess all of the technical attributes necessary to generate electricity from sunlight. Positive and negative charge carriers are released in the cells through light radiation causing electrical current (direct current) to flow.
The "Cell" business division is part of SolarWorld subsidiary SolarWorld Industries Sachsen GmbH, SolarWorld Industries Thüringen GmbH and SolarWorld Americas Inc. Here, solar cells are produced from the preliminary product, the solar silicon wafer. The group manufactures both monocrystalline as well as polycrystalline solar cells.
The monocrystalline as well as polycrystalline solar cells are produced around the clock in one of the most advanced solar cell production facilities. The wafers are produced in the clean rooms of the SolarWorld Industries Sachsen GmbH using the most cutting edge process facilities with the highest level of automation.
Through the fully integrated production concept, it is possible to flexibly control the use of all auxiliary materials necessary for production and to continuously optimize material utilization during operation. This concept allows us to assure the unique quality standard of our solar cells. The solar cells are measured automatically to 100 percent – all together over 150 parameters - and on results and optical criteria sorted. This not only lowers production costs, it adds to the expertise in the solar cell production for the SolarWorld Group.
The wafer is first cleaned of all damage caused by cutting and then textured. A p/n junction is created by means of phosphorous diffusion which makes the silicon conductive. In the next step, the phosphorus glass layer produced by diffusion is removed.
An anti-reflection layer is added. This which reduces optical losses and ensures electrical passivation of the surface is added. Then, the contacts are attached to the front and back along with a rear contact.
Finally, every individual solar cell is tested for its optical qualities and the electrical efficiency measured.