Proceedings of International Conference on Hybrid and Organic Photovoltaics (HOPV24)
DOI: https://doi.org/10.29363/nanoge.hopv.2024.091
Publication date: 6th February 2024
The scientific interest on perovskite solar cells (PSCs) has steadily grown over the last decade – together with their efficiencies – and this technology currently stands as the most promising solution to overcome the limitations of silicon solar-based cells, whether as standalone devices or in tandem with silicon. With PSCs industrialization and worldwide production bound to happen in the near future, it is fundamental to develop suitable recycling protocols that can recover any reusable component and safely handle the residual hazardous waste, thus reducing the overall life cycle impact of this technology.
Among all the materials comprising a PSC, the transparent conductive oxide (TCO) glass substrate is the most promising and suitable component for recovery and reuse, thanks to its high market value, strong physico-chemical stability and easy processability. In literature this task is commonly achieved via chemical dissolution of the PSC layers using DMF or other efficient yet hazardous solvents; in this work we report the use of acetone as an inexpensive, green solvent to recover the TCO glass substrate from different PSC architectures, resulting in a recycling process with a reduced economic and environmental impact. The quality of the TCO glass substrates thus recovered is assessed using different characterization techniques (UV-vis spectrophotometry, Raman spectroscopy, XPS, ToF-SIMS), to measure the key properties of the components after the treatment and to probe their surface for residuals and contaminants; by increasing the reaction time to compensate for its slower dissolution kinetics, acetone is able to achieve satisfactory levels of surface cleaning and contaminants removal, comparable to a DMF-based benchmark. Finally, the effectiveness of our recycling process is validated by fabricating new PSCs using the recovered TCO glass substrates: the photovoltaic performance of these "recycled" devices are very close to those of brand new devices, with a remaining factor above 96%. These results showcase not only the viability of an acetone-based PSC recycling process, but also the clear benefits provided by the use of a more sustainable solvent.