NOVELTY - An aluminum paste comprises: particulate aluminum, an organic vehicle and at least one glass frit selected from (i) lead-free glass frits with a softening point temperature of 550-611 degrees C and containing silica (SiO2) (11-33 wt.%), alumina (Al2O3) (greater than 0 to 7 wt.%) and boron trioxide (B2O3) (2-10 wt.%) and (ii) lead-containing glass frits with a softening point temperature of 571-636 degrees C and containing lead(II) oxide (PbO) (53-57 wt.%), SiO2 (25-29 wt.%), Al2O3 (2-6 wt.%) and B2O3 (6-9 wt.%).    USE - For production of a passivated emitter and rear contact (PERC) silicon solar cell (claimed).    ADVANTAGE - The aluminum pastes allow for the production of passivated emitter and rear contact (PERC) silicon solar cells with improved electrical efficiency. The fired aluminum pastes adhere well to the back-side perforated passivation layer and thus give rise to a long durability or service life of the PERC silicon solar cells produced with the aluminum pastes. The aluminum pastes do not or not significantly damage the perforated dielectric passivation layer on the silicon wafer's back-side and/or exhibit no or only reduced escaping of aluminum-silicon alloy through the perforations in the silicon wafer's back-side passivation layer during firing.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following:    (1) production (P1) of a passivated emitter and rear contact (PERC) silicon solar cell involves: (a) providing a silicon wafer having an antireflective coating (ARC) layer on its front-side and a perforated dielectric passivation layer on its back-side, (b) applying and drying the aluminum paste on the perforated dielectric passivation layer on the back-side of the silicon wafer, and (c) firing the dried aluminum paste, whereby the wafer reaches a peak temperature of 700-900 degrees C;    (2) PERC silicon solar cell made by the process (P1); and    (3) a PERC silicon solar cell comprising an aluminum back electrode where the aluminum back electrode is produced making use of the aluminum paste.