(left) Implied V_oc for asymmetric lifetime samples with LPCVD polysilicon layer and Al₂O₃/SiN_x ARC, measured after contact firing without any metallization for different firing set temperatures. The inset shows a schematic cross section of the samples. (right) I-V results of solar cells with AgAl front side metallization, fabricated in the same experiment and without any LECO treatment. The number next to the box plots refers to the group size.