Proceedings of MATSUS23 & Sustainable Technology Forum València (STECH23) (MATSUS23)
DOI: https://doi.org/10.29363/nanoge.matsus.2023.180
Publication date: 22nd December 2022
Research interest in all inorganic lead halide perovskite nanocrystals (LHP-NCs), featuring general chemical formula of CsPbX3, has recently grown fast thanks to their outstanding chemical and physical properties that make them optimal candidates for a wide range of technological applications such as photovoltaics1, light emitting devices2 and photodetectors3. In this fast-growing and heterogeneous playground, we report a robust, reproducible, and easy scalable synthetic method allowing the production up to the unprecedented scale of 8g of high quality CsPbBr3 NCs for either fundamental studies or in-solution and device applications. To this aim, we modified the synthetic procedure reported by Akkerman et al. 4 by introducing, for the first time, the use of a turbo emulsifier (Ultra Turrax Homogeneizer) usually employed for the preparation of large batches of formulates, to improve the reaction mixture homogenization and overcome concentration gradients and reproducibility issues that usually affect LHP-NCs liter-scale reaction volumes. We also introduced tetrabutylammonium bromide (TBAB) as extra bromide precursor: working in halogen rich environment is known to help reducing defectivity and this specific quaternary ammonium salt is too bulky to be competitive with other cations in the perovskite crystal lattice. We demonstrated that the amount of recovered solid material is proportional to the volume of solution used at every scale, suggesting that the process is well controlled up to the biggest scale. There are also evidences that increasing the scale, magnetic stirring becomes insufficient where turbo-emulsifier remains reliable. Moreover, the procedure is easy extendable to CsPbCl3 and mixed phase and other acid and amine ligands. We further pushed the limit by demonstrating that, with our approach, the low-boiling solvents and the excess reactants, in particular lead bromide, can be recovered and reused, thus reducing the environmental impact connected to waste production and moving a step towards final industrial application. We finally preliminary tested radioluminescence properties both in solution and in polymer matrix to apply them to scintillation field: the big amount that can be easily produced, in one pot, with low waste favors many applications, especially the production of wide scintillating windows even with at high concentration.