Evaluation of multiple cation/anion perovskite solar cells through life cycle assessment
After the great initiation of perovskite as a photovoltaic material, laboratory efficiencies similar to those of other photovoltaic technologies already commercialised have been reached. Consequently, recent research efforts in perovskite solar cells have been directed towards improving their stability as well as making their industrialisation possible. Record efficiencies in perovskite solar cells (PSCs) have been achieved using as the active material a multiple cation/anion perovskite by combining not only methylammonium (MA) and formamidinium (FA), but also the Cs cation and I and Br as anions, materials that have also demonstrated superior stability. Herein, the environmental performance of the production of such perovskite films was evaluated via life cycle assessment. Our study points out that multiple cation/anion perovskite films show major detrimental environmental impacts for all categories assessed, except for abiotic depletion potential, when they are compared with a canonical perovskite, MAPbI3. In addition, a closer analysis of the materials utilised for the synthesis of the different multiple cation perovskite compositions revealed that lead halide reagents and chlorobenzene produced the most adverse results in terms of impact. However, the former is used in all perovskite compositions and the latter can be avoided by the use of alternative fabrication methods to the anti-solvent method. To this end, FAI, with the current synthesis procedures, is the most decisive compound as it increases significantly the impacts and the c ost in comparison with MAI. A further economic analysis revealed that multiple cation perovskites need a significantly higher photoconversion efficiency to produce the same payback times compared to the canonical perovskite.