The production of solarpanels can be divided into two different technologies: wafer-based and thin film.
In wafer-based solar cell production, the first vacuum step lies the manufacturing of the silicon wafers. These are cut out of mono- or polycrystalline ingots, which are produced under vacuum in DSS or Czochralski crystal growing processes (for more details see crystal pulling).
Another important vacuum step is the Physical Vapor Deposition of Transparent Conductive Oxyde (PVD TCO) coating step, which is sputtered on the front and backside of the layer stack.
In thin film solar cell production, two major technologies exist: CIGS (Copper, Indium, Gallium, Selenium) and CdTe (Cadmium, Tellurium). Both active layer stacks are applied in a vacuum coater in several process steps. Once again, the PVD TCO coating is sputtered on the front and backside of the layer stack.
The new technology of heterojunction (HJT) combines Chemical Vapor Deposition (CVD) steps with the well-known PVD front- and back contact coating. The CVD coating steps are applied on an amorphous or microcrystalline basis. Within this technology, Leybold has a large number of installed pumps around the world.
All vacuum processes are typically conducted in large inline coating machines, which operate with the shortest cycle times. Leybold has supported this technology from the beginning and has amassed extensive expertise. For fast load lock pumping, Leybold has specifically developed its POWERBOOST system. Other specialized DRYVAC/RUVAC pump systems are proven as the most reliable solutions for the demanding applications like CIGS and CdTe and ensure the highest factory uptimes.
Even more demanding is HJT, as this process generates large quantities of dust and uses toxic doping gases in addition to H2. The DRYVAC excels here, as it’s hermetically sealed, and the pump materials are specifically selected to handle such processes.