The last five years have seen an unprecedented rise in the efficiencies of lead-based organometal halide perovskite solar cells, which now exceed 22% and match the best thin film device technologies that have been developed over several decades. The record device efficiencies, earth-abundant constituent elements, and potential for low-cost processing have led to great enthusiasm for this technology and hopes of rapid commercialization. However, the necessity of using acutely toxic lead has caused concern. Current opinion within industry, academia and government ranges from the assertion that any use of lead is unacceptable to the belief that the lead intensity will be small and the risks minimal. Given this dichotomy, the primary objectives of this project are: (1) to assess the environmental sustainability of lead halide perovskite photovoltaics (PVs), and (2) to apply this assessment to inform and direct future research, development, and manufacturing approaches related to perovskite PVs.
The data-driven approach to be employed centers on environmental sustainability and life cycle assessment (LCA) of lead-based perovskite PVs with materials and processing methods of real industrial relevance. Environmental impacts of lead perovskite solar cells will be assessed throughout their life cycle, including extraction of materials, manufacturing of PV modules, deployment and operation of modules, and end-of-life recycling. LCA will focus primarily on metrics related to carbon and lead intensity, including greenhouse gas emissions, energy payback time, and heavy metal emissions. Specific aims include: (1) Developing a life cycle inventory for lead halide perovskite PVs with materials and processing methods that are industrially relevant, enabling PVs with high efficiency, long operational lifetimes, highrate manufacturing, and low cost; (2) Evaluating LCA results for a variety of perovskite PV device designs and manufacturing routes to identify the most environmentally sustainable pathways to commercialization; (3) Quantifying heavy metal and carbon intensity for perovskite PVs and comparing to other PV technologies such as CdTe and Si with and without lead-based solder and to lead-emitting fossil-fuel life cycles. Efficient, low-cost solar cells based upon lead halide perovskites have the potential to transform the US and global energy portfolio and improve energy security if they can be manufactured, operated, and retired in an environmentally sustainable manner. This project has the potential to impact the future of PV manufacturing by providing industry, policy-makers, and academia with insights necessary to choose which, if any, lead-based solar cell life cycles are environmentally sustainable. Research will be integrated into multiple courses and senior design projects at Drexel and Columbia. Outreach will extend to underserved K-12 students through expansion of the Junior Solar Sprint program in the West Philadelphia Promise Zone, where the poverty rate is over 50%.
