Mechanochemical Synthesis and Thin-Film Deposition of Zero-Dimensional Cesium Lead Mixed-Halide Perovskites for Wide-Range Color-Tunable Emission

Metal-halideperovskites possess synthetic tunabilityin termsof their compositions and structures, which results in a facile controlof the properties crucial for optoelectronic device applications.For instance, the optical band gap of perovskites can be adjustedby means of halide compositions, which can generate a wide range ofperovskite phases emitting visible light from purple to red. Furthermore,embedding the emissive perovskites within inorganic structural matricesprovides further opportunities to tune their functionalities. In thisstudy, we demonstrate that mechanochemical synthesis (MCS) can besuccessfully employed to prepare a full range of mixed-halide zero-dimensional(0D) perovskites (Cs4PbCl (m) Br6-m and Cs4PbBr6-m I (m) , where m is an integer from 0 to 6). The synthesized mixed-halide 0D perovskitepowder samples exhibited photoluminescence emissions spanning theentire visible spectrum (410-690 nm), which likely originatesfrom the inclusion of three-dimensional perovskites. Furthermore,we demonstrate that our 0D perovskite powder samples can be readilyused as the source for fabricating thin films via fast single-sourcevacuum deposition while preserving the optical properties of the sourcepowder samples. Overall, our study reveals the versatility of MCSas a useful toolkit for preparing a family of 0D perovskites witha full range of halide compositions with potential for light-emittingapplications.

Automated summary

Metal-halide perovskites with synthetic tunability can control the crucial properties for optoelectronic device applications. By adjusting the halide compositions, the optical band gap of perovskites can be modified to emit visible light in a wide range of colors. In this study, we successfully synthesized a series of mixed-halide zero-dimensional perovskites using mechanochemical synthesis, and demonstrated their unique optical properties. Moreover, we showed that these perovskite powder samples can be used for fabricating thin films via vacuum deposition. Overall, our research reveals the versatility of mechanochemical synthesis in preparing different compositions of zero-dimensional perovskites.