SBIR Phase II: Low-Cost, Nickel-Based Metallization Pastes for Solar Cell Applications

The broader impact/commercial potential of this Small Business Innovation Research (SBIR) Phase II project goes well beyond lowering the metallization costs for silicon photovoltaic (PV) cells. In the PV space, the introduction of nickel based metallization pastes can make solar cell modules cheaper and more sustainable. With global demand for energy expected to increase by approximately 40% from its current level of 17 terawatts (TW) to 24 TW by 2035, PV module production must increase from 35 gigawatts (GW) per year in 2013 to>150 GW per year to satisfy a meaningful portion of this new demand. Silver based metallization pastes used in solar cells currently consume 5% of all annual silver production, making large increases in PV production unsustainable in the long-term. In addition, the fundamental mechanism of protecting base metal particles from oxidation at elevated temperatures has far reach implications that can address problems in the integrated circuits and electromagnetic interference shielding industries. This Small Business Innovation Research Phase II project will commercialize nickel (Ni) based metallization pastes as replacements for silver (Ag) metallization pastes on silicon photovoltaic (PV) cells. Silver (Ag) based metallization pastes are used in over 90% of solar cells being manufactured today. However, the high cost of Ag results in the pastes accounting for roughly 7-10% of the cost of the completed silicon solar cell, making alternatives to Ag highly desirable. The spot price of nickel is fifty times less than Ag and orders of magnitude more abundant. Previous attempts to use Ni in metallization pastes have failed due to the rapid oxidation of Ni particles in air when fired at normal processing temperatures for solar cells. This Phase II project will commercialize a technology that protects the Ni particles in the metallization paste from oxidation while allowing the resulting conductive film to remain solderable for connecting cells together in a module. During this project the nickel-based metallization paste will be scaled up and tested on pilot lines of large silicon PV cell makers and show equivalent performance, yield and reliability when compared to standard Ag metallization pastes.