Advanced materials for emerging photovoltaic systems – Environmental hotspots in the production and end-of-life phase of organic, dye-sensitized, perovskite, and quantum dots solar cells

Abstract

Emerging photovoltaic systems (EPVs) such as organic solar cells, dye-sensitized solar cells, perovskite solar cells, and quantum dots solar cells are currently under development, opening up new fields of application due to their lightweight and flexible design and low-cost production. To assess the environmental sustainability of innovations or advanced materials for EPV technologies, it is necessary to consider the entire life cycle. Life cycle assessments (LCAs) can identify materials and manufacturing processes that contribute most to the environmental impact of the overall product. LCAs performed so far are often difficult to compare and have limitations due to different methods and system boundaries, but they show that EPV fabrication may lead to lower energy demand and shorter energy payback time compared to conventional PV technologies. Concerning the materials, energy, and chemicals used, however, the reviewed LCAs also reveal some “environmental hotspots”. There is still room for optimization in terms of environmental sustainability and the circular economy, particularly because of the current use of critical raw materials, precious metals, and toxic as well as energy-intensive materials. In the sense of the safe- and sustainable-by-design approach, not only environmental compatibility but also recyclability should already be considered in the design phase of EPVs. The challenge in developing EPVs is to find a compromise between the highest power conversion efficiency, best stability, and longest service life under real-life conditions, economic interests, and sustainability of all materials and chemicals applied along the whole life cycle of an EPV system.