Screw Dislocation-Driven Growth of the Layered Spiral-type SnSe Nanoplates

A high degree of control over thickness, size, structure, and symmetry of two-dimensional layered materials is essential to tune their chemical and physical properties for applications. Here, we report screw dislocation-driven growth of layered spiral-type SnSe nanoplates with atomically thin helical periodicity for the first time. The spirals are composed of a few connected SnSe layers with decreasing areas; each basal plane has a rectangular shape and spirals up layer by layer to the summit center. The unique structure and growth mode were further confirmed to include herringbone contours, spiral arms, and hollow cores. In addition, the growth mode can be tuned from screw dislocation-driven growth to layer-by-layer growth by manipulating the precursor concentration. The results shown here may provide valuable guidance for the design and growth of unique nanostructures in SnSe or even other two-dimensional layered materials and promote their applications.