Growth and Characterization of PDMS-Stamped Halide Perovskite Single Microcrystals

Recently, halide perovskites have attracted considerable attention for optoelectronic applications, but further progress in this field requires a thorough understanding of the fundamental properties of these materials. Studying perovskites in their single-crystalline form provides a model system for building such an understanding. In this work, a simple solution-processed method combined with PDMS (polydimethylsiloxane) stamping was used to prepare thin single microcrystals of halide perovskites. The method is general for a broad array of materials including CH3NH3PbBr3, CH3NH3PbCl3, CH3NH3Pb(Br0.5Cl0.5)(3), CH3NH3Pb(Br0.75Cl0.25)(3), CsPbBr3, Cs3Bi2Br9, and Cs3Bi2I9. Electron backscatter diffraction (EBSD) was used to investigate the microstructure of the crystals. In order to characterize the microcrystals of CH3NH3PbBr3 electrically, the crystals were grown on prefabricated electrodes creating single-crystal devices contacted from the back. This back-contacted platform circumvents the incompatibility between halide perovskites and the aqueous chemistry used in standard microfabriation processes. It also allows in situ characterization of the perovskite crystal while it operates as a microscopic solar cell.