PolySi Based Passivating Contacts Enabling Industrial Silicon Solar Cell Efficiencies up to 24%

Abstract

In this paper we present our recent results on n⁺, p⁺ and intrinsic polysilicon contacts, including their contacting with industrial metallization process by screen printed fire-through pastes. The review is complemented by comparison with polysilicon passivation results by other relevant players in this field. We present record surface passivation levels on textured surfaces (J0~1 fA/cm² for n⁺ polySi and J0<10 fA/cm² for p⁺ and i-polySi), and record low contact recombination for screen printed fire-through metal contacts reaching down to 65 and 200 fA/cm² for n⁺ and p⁺polySi, respectively. In addition, an improvement in the silicon bulk passivation can be attributed to the introduction of n⁺ polysilicon in the cell process. These results are the fundamental components to demonstrate a roadmap towards 24% industrial PERPoly (industrial TOPCon) cells.