Optically Transparent Lead Halide Perovskite Ceramics

In this report, 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). We additionally expect this method to be broadly applicable to a large swath of metal halide perovskites and not just the compositions shown here. Highly scalable methods to produce polycrystalline lead halide perovskite ceramics will enable key advancements in critical perovskite-based technologies (e.g., direct X-ray/-ray detectors, scintillators, nonlinear optics). In addition to ceramic 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 light scattering theory. In tandem, experiments and modelling illustrate the effects of scattering sources on transparency and reveal microstructural parameters necessary to attain near optimal transparency in perovskite polycrystalline ceramics.