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We demonstrate industrially feasible large‐area solar cells with passivated homogeneous emitter and rear achieving energy conversion efficiencies of up to 19.4% on 125 × 125 mm2 p‐type 2–3 Ω cm boron‐doped Czochralski silicon wafers. Front and rear metal contacts are fabricated by screen‐printing of silver and aluminum paste and firing in a conventional belt furnace. We implement two different dielectric rear surface passivation stacks: (i) a thermally grown silicon dioxide/silicon nitride stack and (ii) an atomic‐layer‐deposited aluminum oxide/silicon nitride stack. The dielectrics at the rear result in a decreased surface recombination velocity of Srear = 70 cm/s and 80 cm/s, and an increased internal IR reflectance of up to 91% corresponding to an improved Jsc of up to 38.9 mA/cm2 and Voc of up to 664 mV. We observe an increase in cell efficiency of 0.8% absolute for the cells compared to 18.6% efficient reference solar cells featuring a full‐area aluminum back surface field. To our knowledge, the energy conversion efficiency of 19.4% is the best value reported so far for large area screen‐printed solar cells. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

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We have implemented a baseline solar cell process based on today's standard industrially manufactured silicon solar cells. Using this process, we achieve conversion efficiencies up to 18.5% applying 125 Â 125 mm² pseudo-square p-type 2-3 Ω cm boron-doped Czochralski silicon wafers featuring screen-printed front and rear contacts and a homogenously doped 70 Ω/□ n + -emitter. Optimizing a print-on-print process for the silver front side metallization, we reduce the finger width from 110 to 70 mm, which increases the conversion efficiency up to 18.9% due to the reduced shadowing loss. In order to further increase the efficiency, we implement two different dielectric rear surface passivation stacks: (i) a silicon dioxide/ silicon nitride stack and (ii) an aluminium oxide/silicon nitride stack. The rear contacts to the silicon base are formed by local laser ablation of the passivation stack and aluminium screen printing. The dielectric layer stacks at the rear decrease the surface recombination velocity from S eff,rear = 350 cm/s for a full-area Al back surface field down to S eff,rear = 70 cm/s and increase the internal reflectance from 61% up to 91%. The improved solar cell rear increases the conversion efficiency up to an independently confirmed value of 19.4%, the short-circuit current density J sc up to 38.9 mA/cm² and the open-circuit voltage V oc up to 662 mV. The detailed solar cell analysis reveals potential to further increase the conversion efficiency towards 20% in the near future.