NOVELTY - Applying (m1) a back contact silver busbar (6) to an aluminum back surface field (BSF) of a solar cell involves printing a full aluminum backing layer on back side of substrate (2); drying the backing layer; printing and drying a peeling paste on full aluminum layer in areas where silver busbar is desired; printing and drying a front contact silver paste on the substrate front side to produce a front grid electrode; co-firing and cooling the front and back sides of the solar cell; and printing, drying and firing a back contact silver paste on the open areas of the BSF.    USE - For applying a back contact silver busbar to an aluminum back surface field (BSF) of a solar cell (claimed).    ADVANTAGE - By using the present method, cell performance is improved due to higher open circuit voltage, and the cell maintains its reliability due to good adhesion and solderability of low temperature firing back contact silver busbars to the substrate. The solar cells produced according to the present method also have a desirable full BSF. The BSF functions to reduce electron-hole recombination at the back of the solar cell, thus increasing cell efficiency. Accordingly, a full BSF improves efficiency of the solar cell.    DETAILED DESCRIPTION - Applying (m1) a back contact silver busbar (6) to an aluminum back surface field (BSF) of a solar cell involves providing a solar cell substrate (2) having a front and back side; printing a full aluminum backing layer on the back side of the solar cell substrate; drying the printed aluminum backing layer to yield a full aluminum layer; printing and drying a peeling paste on the full aluminum layer in areas where silver busbar is desired; printing and drying a front contact silver paste on the front side of the solar cell substrate to produce a front grid electrode; co-firing and cooling the front and back sides of the solar cell, where during firing the peeling paste wets excess aluminum powder in the aluminum layer, such that during cooling of the solar cell, the peeling paste contracts, solidifies, and peels off with the excess aluminum powder to leave a full aluminum BSF having open areas; and printing, drying and firing a back contact silver paste on the open areas of the BSF to yield the silver busbar. The co-firing is performed at a peak temperature of at least 700-800 degrees C. The cooling is performed at a rate of 60-80 degrees C per second. The firing is performed at 500 degrees C. The back contact silver paste fires at less than 550 degrees C. An INDEPENDENT CLAIM is included for a solar cell formed by the method (m1).    DESCRIPTION OF DRAWING(S) - The figure shows a schematic view of a solar cell with partial back surface field.    Silicon substrate (2)    Silver fingers (4)    Silver back contacts (6)    Partial back surface field (8)