Optically Transparent Lead Halide Perovskite Ceramics

We utilize room-temperature uniaxial pressing at applied loads achievable with low-cost, laboratory-scale presses to fabricate freestanding CH₃NH₃PbX₃ (X^-=Br^-, Cl^-) polycrystalline ceramics with millimeter thicknesses and optical transparency up to ~70% in the infrared. As-fabricated perovskite ceramics can be produced with desirable form factors (i.e., size, shape, and thickness) and high quality surfaces without any post-processing (e.g., cutting or polishing). This method should be broadly applicable to a large swath of metal halide perovskites and not just the compositions shown here. In addition to fabrication, we analyze microstructure—optical property relationships through detailed experiments (e.g., transmission measurements, electron microscopy, X-ray tomography, optical profilometry, etc.) as well as modelling based on Mie theory. The optical, electrical, and mechanical properties of perovskite polycrystalline ceramics are benchmarked against single crystalline analogues through spectroscopic ellipsometry, Hall measurements, and nanoindentation. Finally, scintillation from a transparent MAPbBr₃ ceramic is demonstrated under λ-ray irradiation from a ¹³⁷Cs source. From a broader perspective, scalable methods to produce freestanding polycrystalline lead halide perovskites with comparable properties to their single crystal counterparts could enable key advancements in the commercial production of perovskite-based technologies (e.g., direct X-ray/g-ray detectors, scintillators, nonlinear optics).<br/><br/>Reference: Brennan, M. C.; McCleese, C. L.; Loftus, L. M.; Lipp, J.; Febbraro, M.; Hall, H. J.; Turner, D. B.; Carter, M . J.; Stevenson, P. R.; Grusenmeyer, T. A. Optically Transparent Lead Halide Perovskite Polycrystalline Ceramics. <i>ACS Appl. Mater. Interfaces</i><b> 2024</b>, <i>16</i>, 15084-15095. doi.org/10.1021/acsami.4c01517