A photovoltaic solar cell for producing energy from the sun including a germanium substrate including a first photoactive junction and forming a bottom solar subcell; a gallium arsenide middle cell disposed on said substrate; an indium gallium phosphide top cell disposed over the middle cell; and a surface grid including a plurality of spaced apart grid lines, wherein the grid lines have a thickness greater than 7 microns, and each grid line has a cross-section in the shape of a trapezoid with a cross-sectional area between 45 and 55 square microns.
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