Large Area TOPCon Technology Achieving 23.4% Efficiency

We report on the development of the TOPCon technology on large area focusing on the deposition technology for the a-SiC x (n) layer and the rear side metallization. We demonstrate that kHz direct-plasma technology can be used to deposit the a-SiC x (n) layers and that concerns about ion bombardment damaging the thin SiO x are not justified. Excellent surface passivation quality was achieved with lifetimes up to 13 ms (1 Ocm n-type). The layers can be contacted using ITO reaching specific contact resistivities in the range of 5 mOcm 2 . Solar cells with a boron diffused emitter and TOPCon rear are presented resulting in an efficiency of 23.4 % with laser contact opening and NiCuAg plating.