By Marc Hofmann, Head of the Plasma Technology and Surface Passivated Solar CellsTeam, Fraunhofer ISE; Jochen Rentsch, Head of the Wet Chemical and Plasma Technologies, Fraunhofer ISE; Stefan W. Glunz, Head of the Department for Silicon Solar Cells,Fraunhofer ISE; Ralf Preu, Head of the Department for PV Production Technology and Quality Assurance, Fraunhofer ISE
Amorphous silicon is one of the most effective materials in passivating silicon interfaces. At Fraunhofer ISE, highly passivating amorphous silicon coatings were developed by an industrially applicable Plasma-Enhanced Chemical Vapour Deposition (PECVD) process. Thin-film stacks of amorphous silicon and SiOx display excellent passivation quality, indicated by effective charge carrier lifetimes ranging from 900 to 1600µs and resulting surface recombination velocities between 9 and 3cm/s-1. The demonstrated temperature stability opens up new application opportunities also for amorphous silicon films in the industrial production of highly efficient solar cell structures, which will be further discussed in this paper.