Structural Characterization and Optical Properties of Perovskite Crystals Based on Micro-Hyperspectral Imaging Sensor

Micro-hyperspectral imaging (MHSI) is an advanced sensor technology that exploits the distinct spectral signatures of samples for characterization, analysis, and identification. However, applying MHSI to the studies of materials at microscale and nanoscale remains constrained. Perovskite, an innovative material, has attracted widespread attention due to its exceptional optical properties, and the characterizing utilization of MHSI on microscale and nanoscale perovskite crystals represents a novel perspective for further comprehensive analysis of the optical characteristics of perovskite. In this study, we developed a home-built MHSI sensor system through the integration of a hyperspectral imaging (HSI) sensor and a metallurgical microscope, enabling the acquisition of 3-D data of the microscale perovskite crystals (MAPbBr(3)) samples, which including the characterization imaging of the morphological structure of the samples and its high-resolution spectral response values for hundreds of spectral bands. Auxiliary verification methodologies, including white light interference (WLI), energy-dispersive spectroscopy (EDS), and COMSOL simulation, were employed for the cross-analysis of complex interrelationships among compositional ratios, thickness, morphology, and optical properties in perovskite crystals (MAPbBr(3)) and to substantiate the data acquired by MHSI. Specifically, the relationship between thickness and elemental ratios of the crystal has been investigated to explain the optical properties of the "fishbone" sample, and morphology features have been studied to verify the optical properties of the "pyramid" sample. The strong correlation between the experimental results and auxiliary verification highlights the immense potential of MHSI sensor technology for the characterization and extensive in-depth optical analysis of micro-nano materials.