Spectroscopic and High-speed X-ray Analysis of Perovskite Evolution for Tailored Nanocrystal Engineering (SHAPE)

• Applicants: Dr. Bert Nickel; Professor Dr. Alexander Urban
• Subject Area: Experimental Condensed Matter Physics ; Physical Chemistry of Solids and Surfaces, Material Characterisation
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 564997836

This project aims to revolutionize the synthesis and optimization of halide perovskite nanocrystals (PNCs) by tailoring their size, shape, and optical properties for scalable applications in optoelectronic devices. PNCs, particularly CsPbBr₃ nanocrystals, exhibit exceptional tunable bandgaps, high quantum yields, and straightforward synthesis, making them promising candidates for advanced technologies. However, the mechanisms underlying their rapid synthesis and shape evolution are poorly understood, limiting the ability to control their properties reliably. This project focuses on four interconnected objectives: understanding and tailoring the morphology and composition of precursor micelles that serve as the foundation for nanocrystal growth, investigating the rapid formation of anisotropic intermediate nanoclusters upon precursor mixing, elucidating how antisolvent-induced processes guide nanocluster assembly into specific shapes, and enhancing optical properties and stability through post-synthetic treatments, such as ligand exchange and strategies to prevent environmental degradation. The research employs advanced in-situ and ex-situ characterization techniques, including small- and wide-angle X-ray scattering (SAXS/WAXS) and photoluminescence (PL) spectroscopy, integrated with flow chemistry and machine learning to optimize synthesis parameters and enable more profound exploration of the synthetic landscape. The study will systematically unpack the rapid processes driving nanocrystal formation by combining these methods. Precursor micelles will be tailored by varying synthetic parameters, with their morphology characterized through SAXS and total scattering. Intermediate nanoclusters' rapid formation and stability will be investigated using in-situ experiments with millisecond temporal resolution. The role of antisolvents in mesophase formation and their influence on nanocrystal geometries and optical properties will also be examined. Post-synthetic treatments will focus on enhancing stability and quantum yields while providing insights into degradation pathways and strategies for long-term durability. This collaborative effort, leveraging the complementary expertise of two expert groups, aims to establish a framework for the rational design of anisotropic PNCs and bridge the gap between basic research and commercial applications. The ultimate goal is to achieve gram-scale, reproducible synthesis of high-quality nanocrystals with exceptional optical properties. This will enable the commercialization of perovskite-based technologies in next-generation displays, lighting systems, and optoelectronic devices. This comprehensive approach positions the project to deliver transformative advancements in the field.

• DFG Programme: Research Grants