Advancements in the Utilization of Screen-Printed Boron Doping Paste for High Efficiency Back-Contact Back-Junction Silicon Solar Cells

Screen printed boron doping paste can be used as a cost-effective and highly flexible dopant source in silicon photovoltaics. In combination with a co-diffusion approach, it can help mitigate some of the increased costs advanced solar cell concepts inherit. Aiming at the fabrication of high efficiency back-contact back-junction solar cells, we investigate the limitations of direct structured application regarding minimal feature sizes. We find minimal feature sizes of 75 and 120 mm for n ++ - and p ++ -doped regions, respectively. We also demonstrate a fully compatible and homogeneous (DROS/ROS = 3% rel ) co-diffusion process, creating all dopings at once.