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In this work, we improved the performance of the MWT-PERT solar cells focusing on increasing their V-oc by combining the MWT concept with n-PERT technology. The impact of different post-laser treatments on the via surface morphology and the via passivation was investigated. KOH texturing can partially remove the laser damage in the via and reduce the via SRV to 1000 cm/s. With optimized post-laser treatment and via passivation, an average V-oc of 685mV was achieved for our large-area n-type MWT-PERT cells. Front Ni/Cu plating and rear Ag and Al screen-printing were used for the metallisation, the compatibility of this hybrid metallisation scheme was studied. Using industrial solder-through interconnection technology, the cell was integrated in a laminate reaching a one-cell module efficiency at 20%. The reliability of the one-cell modules was preliminarily investigated in an extended reliability test. (C) 2017 The Authors. Published by Elsevier Ltd. The authors gratefully acknowledge the financial support of the PV4FACADES project (Solar-Era.net) and Imec's industrial affiliation program for Photovoltaics (IIAP-PV).

This work evaluates the potential of selective epitaxy to mitigate the recombination losses at the p-type contact regions of plated bifacial n-type PERT cells. Following the growth of a 500 nm, 2.5 10(19) cm(-3) boron doped epitaxial layer at the emitter contact regions defined by laser ablation of the passivating dielectrics, both an increase in V-oc (+6 mV) and FF (+ 1% absolute) are measured in the final cells compared to the reference with a homogeneous diffused emitter. These results come with an average efficiency gain of 0.3 and 0.5% absolute for front and rear side illumination, respectively. If the diffused, blanket emitter in the passivated regions is replaced by a thicker, lowly doped epitaxial profile (3 mu m, 5 10(18) cm(-3)) to further reduce recombination, an additional rise in implied V-oc after metallization of 10 mV is estimated. This increase would be the result of a reduction in J(0,pass, emitter) (down to 6 fA/cm(2)) and J(0,plated, emitter) (down to 1967 fA/cm(2)).