Proceedings of International Conference on Hybrid and Organic Photovoltaics (HOPV24)
DOI: https://doi.org/10.29363/nanoge.hopv.2024.038
Publication date: 6th February 2024
Interest in wet chemical synthesis to produce metal halide perovskite powder has increased in recent years because it subsequently allows for easy production of large quantities of perovskite crystals. These crystals can then be used to produce thin perovskite films for solar cells which exhibit high stability and performance [1,2]. The stoichiometric homogeneity achieved by the crystallisation process in the alcohol dispersions simplifies thin film deposition and therefore improves photovoltaic device performance over large areas. In this study we characterize the formation of metal halide perovskite in environmentally friendly alcohols using in situ wide and small angle X-ray scattering to compare the perovskite formation in methanol, ethanol, propan-2-ol and pentanol. The different alcohols are used as solvents for precipitation reactions forming methyl ammonium lead iodide MAPbI3 and methyl ammonium formamidinium lead iodide MA0.5FA0.5PbI3 perovskites. Time resolved in-situ small and wide X-ray scattering (SAXS and WAXS) permits the reaction of the dissolved methylammonium iodide and formamidinium iodide with the suspended lead iodide to form perovskite to be followed in real time, and provides evidence of the mechanism by which the structural assembly from precursors to perovskite occurs. These measurements led to a deeper understanding of intermediate steps during the reaction, where particle morphology control is possible during the perovskite material assembly. The production of metal halide perovskite by precipitation as described in this work is cost-effective and has fewer safety issues due to the low solvent toxicity. This work outlines an alternative processing route to make stable perovskites for photovoltaics.
This work was supported by funding from the SUPERGEN SuperSolar International and Industrial Engagement Fund and an allocation of beamtime on i22 at the Diamond Light Source - experiment number SM29997-1. Thanks to Dr Thomas Zinn for help with the experimental setup and data acquisition.