This paper reports on the fabrication of high efficiency (similar to 20%) front junction n-type Si solar cells on 239 cm(2) Cz using ion implanted boron emitter and phosphorus back surface field (BSF) in combination with screen printed metallization. Cell efficiencies of 19.8% and 20.0% were achieved with SiO2/SiNx and Al2O3/SiNx passivation of boron implanted emitter, respectively, supporting the superiority of Al2O3 passivation. This is consistent with low boron emitter saturation current densities of 76 and 45 fA/cm(2) achieved for boron emitter passivated with SiO2/SiNx and Al2O3/SiNx stacks, respectively. Saturation current density in metal contact area of boron emitter and phosphorus BSF was measured directly by varying the metal contact coverage. Detailed analysis of saturation current density showed that the performance of our 20% is largely limited by saturation current density associated with recombination on metal contact area of boron emitter and bulk of phosphorus BSF, which accounted for almost 50% of the total saturation current density. (C) 2014 Elsevier B.V. All rights reserved.