Transitioning from legacy fossil fuels to alternatives will require deploying a multipronged strategy seeking energy harvesting, storage, and consumption innovations. One class of materials that may satisfy these societal needs are metal halide perovskite and perovskite-like compounds. Perhaps the most ubiquitous perovskite in the literature today is methylammonium lead iodide (MAPbI3). However, this area continues to evolve rapidly due to the immense chemical and synthetic variability possible at the A, B, or X positions and the dimensionality. While metal halide perovskites are defect tolerant, they can suffer from domain formation, phase changes or decomposition, often associated with moisture or heat. This behaviour for hybrid and inorganic materials is rooted in intrinsic dynamics and local structural disorder, which is difficult to track via traditional characterization approaches. Solid-state nuclear magnetic resonance (NMR) spectroscopy is a robust, non-destructive, and nucleus-specific characterization method for local- and medium-range atomic structure and dynamics that continues to fill in these missing clues, an area we have spent nearly a decade in developing. 

This presentation discusses how an interdisciplinary approach that combines physical, solid-state, and materials chemistry can help to solve the complex structure, dynamics, and structure-property relationships of perovskite and perovskite-inspired materials. Our recent efforts in developing solvent, high temperature, and mechanochemical methods to improve long-term stability and identify lead-free (Sn, Ge, etc.) perovskite and perovskite-inspired (double, vacancy ordered, etc.) materials will be presented. The far-reaching chemical diversity of metal halides is attractive, leading to a host of optoelectronic materials with suitable physical and optical properties. Our research focuses on developing effective characterization strategies to understand how atomic-level modifications influence physical and optical behaviour. We will discuss recently developed methods using magnetic resonance spectroscopy techniques such as solid-state NMR, high-field dynamic nuclear polarization (DNP), and electron paramagnetic resonance (EPR) that can aid perovskite researchers in understanding atomic-level modifications (e.g., ion substitution, dopants, surfaces/interfaces, and ion dynamics). These approaches are coupled with quantum chemical computations, X-ray diffraction, and scanning electron microscopy; together, these data enable us to stitch together a complete instructive structural model spanning Å to µm in scale that can be widely applied to this broad class of compounds.