Life cycle assessment of synthetic pathways for high efficiency organic photovoltaic modules

Organic photovoltaics (OPVs) present a promising and potentially more sustainable avenue to solar energy utilization compared to crystalline solar cells, by using printable materials with minimum energy requirements. However, potential environmental impact reductions need to be evaluated throughout the cradle-to-gate, with many existing studies relying on legacy bibliographic data that are not representative of state-of-the-art advancements from a material and device engineering perspective. This study conducts a life cycle assessment of the synthesis pathways of highly efficient polymeric donors (PCDTBT, PTQ10), used in the active layer of OPVs. We provide new inventory data that can be incorporated in future LCA studies to enable comparative evaluations of this technology to traditional Si-based solar cells. PCDTBT synthesis revealed a GWP100 of 28.6 kg CO2-eq per kg, which is 15 times higher than P3HT. However, in a complete device, the PCDTBT cell has an 8.7% lower impact per Wp due to higher efficiency. By relying on lab-scale primary data, this study provides insights into the trade-offs involved in material design and process optimization, contributing to the identification of sustainable synthetic pathways for OPV materials. These findings demonstrate the importance of life cycle assessment in the early stages of OPV device development to inform environmentally friendly production at scale.