To clarify the differences between high temperature glass/Ag bassed metallization pastes and low temperature metallization pastes used for thin film "shingle" assembly, our own Jim Slattery provided this advice:
"Our LTTF-7888 silver metallization paste is designed for printing on TCOs such as AZO and ITO on thin film photovoltaic solar cells. It features low contact resistance, low bulk resistance and has a low drying temperature of less than 200 deg C. However, this metallization paste is not designed to penetrate the electrically insulating antireflection passivation coatings such as SiN. Higher temperature silver metallization pastes containing glass frit and an etchant are required to penetrate the passivation layer and insure good ohmic contact. These pastes have a reflow temperature peaking in the 1000 deg C range, and normally are used for metallization of single crystal or polycrystalline Si wafer photovoltaics."