ALUMINIUM PASTE WITH NO OR POOR FIRE -THROUGH CAPABILITY AND USE THEREOF FOR BACK ELECTRODES OF PASSIVATED EMITTER AND REAR CONTACT SILICON SOLAR CELLS

摘要

An aluminium paste having no or only poor fire-through capability comprises aluminium particles, at least one glass frit containing 0.5 to 15 wt.% SiO2, 0.3 to 10 wt.% Al2O3 and 67 to 75 wt.% Bi2O3 (the weight percentages being based on the total weight of the glass frit) and an organic vehicle. The aluminium paste is used in the manufacture of aluminium back electrodes of PERC (passivated emitter and rear contact) silicon solar cells, wherein the paste is applied on a perforated dielectric passivation layer on the back-side of a silicon wafer and subsequently dried and fired or, alternatively, wherein the paste is applied on a non-perforated passivation layer on the back-side of a silicon wafer, dried and fired and the aluminium layer and the passivation layer are subsequently laser fired to produce perforations in the passivation layer and to form local BSF (back surface field) contacts.