Improved Screen-Printed Cu Metallisation for Passivated Contact Solar Cells

Abstract

This abstract reports the first results regarding the development of screen-printed curing type Cu paste suitable for low and high temperature passivated contact solar cells. Cu nanoparticles were encapsulated with a thin layer of polyvinylpyrrolidone (<; 5 nm) and screen printed on Indium-Tin oxide (ITO). The screen-printed samples were cured under vacuum conditions (<; 300 ppm O ₂ ) at a range of curing temperatures (180 °C - 450 °C) and durations (15 min - 60 min). Cu pastes were investigated for their printability, microstructure at the metal-ITO interface and electrical (line, contact) resistances. The screen-printed Cu achieved excellent contact resistance values comparable to Ag contacts with best contact resistivity of 0.25 mΩ.cm ² obtained by curing between 400 °C to 450 °C. The following investigations are ongoing: Contact resistance of Cu contacts to ITO at curing temperatures up to 950 °C. Contact resistance to Aluminum Zinc oxide (AZO) and line resistance of Cu at curing temperatures between 180 °C to 950 °C. Final results will be presented at the conference with critical insights with regards to development of low-cost copper screen printing for passivated contact solar cells.