Analysis of a technology for CZ bifacial solar cells

A bifacial cell technology for Cz Si and evaporated contacts is presented. A p(+)nn(+) structure on high resistivity material gives 17.7% for n(+) sid e illumination and 15.2% for p(+) side illumination. Cell performance is an alyzed by fitting experimental measurements with PC1D. Analysis shows that p+ layer puts a limit to cell performance, mainly due to a high surface rec ombination velocity. The boron depleted zone near the surface also enhances recombination, but its effect can be reduced by performing a boron etch-ba ck step in the process. Cells with boron etch-back give higher short-circui t current and a reduction of open-circuit voltage of around 10 mV. These re sults are consistent with the PC1D model.