Metallization is a decisive determinant of the efficiency, material demand, and cost of silicon solar cells. It involves the formation of metallic electrodes on the front and rear surfaces of the cell to collect and transport photogenerated charge carriers. Since the 1980s, screen printing has been the dominant industrial metallization technology because it is robust, cost-effective, and readily scalable for mass production. Over just a few decades, industrial contact-finger widths have decreased from approximately 100 µm to only 10–15 µm.
As the photovoltaic industry expands toward terawatt-scale production, silver consumption has emerged as a major technological, economic, and sustainability challenge. Silver remains a key component of metallization pastes; however, its consumption and price volatility substantially affect the economic viability and resource efficiency of photovoltaic manufacturing. High-efficiency cell architectures such as TOPCon, in particular, require comparatively high silver loadings because both cell surfaces must be contacted. In the long term, reducing silver consumption to below 2 mg Wp⁻¹ is widely regarded as a critical target for sustainable PV production.
In this review, we examine the technological evolution of screen printing for silicon solar cells and the economic and technical forces that have shaped it over recent decades. Our assessment of published data reveals that the pace of innovation in fine-line printing has accelerated markedly since 2013. Key drivers include rising silver prices, the transition from three-busbar designs to multi-busbar and multiwire interconnection concepts, and advances in screen-printing technologies and laser-assisted contact optimization (LECO).
Furthermore, this review identifies promising pathways toward silver-reduced metallization. These include advanced fine-line screen-printing processes, the renewed potential of stencil printing, and contact pastes incorporating alternative metals such as copper, nickel, and aluminum. The findings demonstrate that continued innovation in metallization and cell interconnection will be pivotal to enabling high-performance, resource-efficient silicon photovoltaics at the terawatt scale.
