Solar Energy Materials and Solar Cells, cilt.302, 2026 (SCI-Expanded, Scopus)
Interdigitated back contact (IBC) silicon solar cells enable high-efficiency device architectures but remain challenging to manufacture at industrial scale due to complex patterning requirements involving lithography, laser processing, or ion implantation. In this work, we present a fully screen-printed, lithography- and laser-free manufacturing route for IBC solar cells that is compatible with existing n-type industrial production lines. Selective rear-side junction formation is achieved using patterned silicon nitride (SiNx) layers where a conformal PECVD SiNx layer was deposited and subsequently patterned using a screen-printed acid-resistant etch mask and wet chemical HF etching to enable conventional boron and phosphorus diffusions in standard BCl3 and POCl3 furnaces. The approach avoids dopant pastes and aggressive etching pastes, reducing process complexity and tool compatibility concerns. By optimizing the SiNx composition and thickness, well-defined interdigitated junctions were achieved without evidence of parasitic dopant crossover. Surface passivation was realized using industrially relevant Al2O3/SiNx and SiNx stacks, while rear-side metallization employed fire-through Ag and AgAl pastes activated in a conveyor belt firing furnace. Contact resistivities below 10 mΩ cm2 were obtained for both polarities. First functional IBC cells fabricated using this process achieved efficiencies of 19.3% and 19.1% for front floating emitter and front surface field designs, respectively, on 3 cm2 aperture area devices. Although the demonstrated efficiencies remain below state-of-the-art IBC values, the proposed process provides a scalable and flexible manufacturing route with clear potential for further performance improvement.