Reduced Environmental Controls in Perovskite Solar Cell Manufacturing Enabled by Vacuum-Deposited Gas Barrier Coatings

In recent years, metal-halide perovskites have rapidly become the most promising class of next- generation solar materials, due to their extremely high efficiencies (>20%) and their amenability to cheap manufacturing. With their relative ease of fabrication, potential for roll-to-roll processing and extremely high efficiencies, perovskite solar cells could be a disruptive technology that would put the world on track to meet its targets for solar energy production. Perovskite solar cells, however, are highly susceptible to degradation by exposure to ambient humidity or high temperatures, which poses a major challenge to their effective manufacturing. In order to produce reliable and high-performing solar cells, manufacturers will need to invest in expensive environmental controls (i.e. dry room equipment) to limit the degradation during cell layout, interconnect formation and lamination. They will also need to implement low- temperature lamination methods that do not destroy the perovskite absorber layer. These challenges pose a major technical and economic hindrance to the adoption of this technology to reduce emissions and slow climate change. GVD proposes to use its vacuum-deposited, multilayer, gas barrier coatings to circumvent the need for dry facilities for module assembly and improve the thermal stability of perovskite solar cells. The gas barrier coatings will exclude water vapor from the perovskite, allowing the solar cell module to be assembled in ambient conditions without loss of photovoltaic efficiency. At the same time, the barrier coating will improve the thermal stability of the perovskite by slowing the process that drives decomposition at high temperatures, the evaporation of methylammonium iodide. Reducing the capital equipment required for a perovskite solar cell plant will have a direct and significant impact on the minimum sustainable price and allowing the industry-standard lamination method (ethylene vinyl acetate, 150 °C) to be used will eliminate the need to redesign this crucial step in the manufacturing process. In Phase I, GVD will optimize its coating process to give the highest possible throughput and barrier properties. The barrier coatings’ effect on stability of perovskite solar cells will be evaluated in partnership with Tandem PV (a tandem perovskite solar cell manufacturer) and Prof. Tara P. Dhakal (the director of the Center for Autonomous Solar Power at SUNY Binghamton). At the end of Phase I, GVD will have identified a barrier coating with optimal performance in the proposed application and will be ready to move on to scaling up and refining the process, so that it can be integrated into perovskite solar manufacturing lines.