A Droplet Method for Synthesis of Multiclass Ultrathin Metal Halides

2D metal halides have attracted increasing research attention in recent years; however, it is still challenging to synthesize them via liquid-phase methods. Here it is demonstrated that a droplet method is simple and efficient for the synthesis of multiclass 2D metal halides, including trivalent (BiI3, SbI3), divalent (SnI2, GeI2), and monovalent (CuI) ones. In particular, 2D SbI3 is first experimentally achieved, of which the thinnest thickness is & AP;6 nm. The nucleation and growth of these metal halide nanosheets are mainly determined by the supersaturation of precursor solutions that are dynamically varying during the solution evaporation. After solution drying, the nanosheets can fall on the surface of many different substrates, which further enables the feasible fabrication of related heterostructures and devices. With SbI3/WSe2 being a good demonstration, the photoluminescence intensity and photo responsivity of WSe2 is obviously enhanced after interfacing with SbI3. The work opens a new pathway for 2D metal halides toward widespread investigation and applications.

Automated summary

In recent years, there has been growing research interest in 2D metal halides; however, liquid-phase synthesis methods remain challenging. This study demonstrates a simple and efficient droplet method for synthesizing various types of multiclass 2D metal halides. The nucleation and growth of these metal halide nanosheets are determined by the supersaturation of precursor solutions, allowing for the fabrication of heterostructures and devices. The interfacing of SbI3/WSe2, for example, enhances the photoluminescence intensity and photo responsivity of WSe2. This work opens up new avenues for investigating and applying 2D metal halides.