NOVELTY - A silicon solar cell structure comprises a p-type gallium-doped silicon substrate having a top side and a back side, wherein the bulk lifetime is 20-2500 microseconds.    USE - For use in e.g. orbiting space satellites, remote telecommunication repeaters, fiber optic amplifiers, remote street signs, telephone booths, outdoor lighting, homes, businesses, utility scale power generation.    ADVANTAGE - The silicon solar cell structure has reduced or eliminated light induced degradation, superior ohmic contact, superior solar cell performance and efficiency, and superior Al BSF. It has an absolute efficiency greater than 18% (preferably greater than 20%) after light-induced degradation; a series resistance (Rs) of 0.01-1 Omega-cm2, a shunt resistance of 1000-5000 kOmega, a junction leakage current (Jo2) of 1-10 nA/cm2, and a contact resistance (rhoc) of 0.01-3 mOmega-cm2; and a back surface recombination velocity (BSRV) of 1-600 cm/s.    DETAILED DESCRIPTION - A silicon solar cell structure comprises:    (a) a p-type gallium-doped silicon substrate (114) having a top side and a back side, wherein the bulk lifetime is 20-2500 microseconds;    (b) an n+ layer (104) formed on the top side of the substrate;    (c) a silicon nitride anti-reflective (AR) layer (106) positioned on the top side of the n+ layer;    (d) silver (Ag) contacts (110) positioned on portions of the silicon nitride AR layer, wherein the Ag contacts are in electronic communication with the n+ layer;    (e) a uniform aluminum (Al) back-surface field (BSF) layer (112) having a top side and a back side, wherein the top side of the Al BSF layer is positioned on the back side of the substrate; and    (f) an Al contact layer (108) positioned on the back side of the Al BSF layer.    It has a fill factor (FF) of 0.75-0.85, an open circuit voltage (Voc) of 600-650 mV, and a short circuit current density (Jsc) of 28-36 mA/cm2.    An INDEPENDENT CLAIM is also included for a method for fabricating a silicon solar cell structure comprising:    (i) providing a gallium-doped p-silicon substrate having a top side and a back side;    (ii) forming an n+ layer on the top side of the substrate;    (iii) forming a silicon nitride AR layer on the top side of the n+ layer;    (iv) forming Ag contacts on the silicon nitride AR layer A screen-printing technique;    (v) forming an Al contact layer on the back side of the gallium-doped p-silicon substrate using a screen-printing technique;    (vi) co-firing the gallium-doped p-silicon substrate having the n+ layer, silicon nitride AR layer, Ag metal contacts, and Al contact layer; and    (vii) forming a co-fired silicon solar cell structure, wherein the Ag contacts are in electrical communication with the n+ layer, the silicon solar cell has a fill factor of 0.75-0.85, a Voc of 550-650 mV, and a Jsc of 28-36 mA/cm2.    DESCRIPTION OF DRAWING(S) - The figure shows a silicon solar cell structure.    N+ layer (104)    Silicon nitride AR layer (106)    Al contact layer (108)    Ag contacts (110)    Al BSF layer (112)    P-type gallium-doped silicon substrate (114)