Sputtering of passivated contacts based on the TOPCon technology with the help of industrial equipment technology
Subproject: In-situ sputter processes of highly doted poly-silicon layers
After the industrialization of the PERC cell, the next development step on the technological roadmaps of many companies in the photovoltaics industry is the integration of selective back side contacts that are passivating on the whole surface, as well as, on the long run, the development of tandem solar cells.
For both concepts, charge carrier-selective contact systems are a key technology. The project focuses on the in-situ deposition of n-doted silicon layers by cathode sputtering, which can evidently reach a cell efficiency of ≥ 23.5 % in solar cells with TOPCon structures but with diffused emitter.
In this project, a process sequence for creating a TOPCon layer stack shall be developed that can be implemented on industrial scale, based on a crystalline silicon substrate consisting, preferably, of a wet-chemical boundary layer oxide and a doted poly-crystalline silicon thin-film and, optionally, a silicon nitride. This shall be achieved with the help of high-throughput PVD equipment.