Study of morphological evolution and growth mechanism of CVD grown 2D tin disulfide

Abstract

Fractal patterns formed during non-equilibrium growth processes and are abundant in nature. However, the mechanism of their formation remains unknown. Several growth factors such as relaxation rate, cooling rate, diffusion anisotropy and growth time were identified for regulating the fractal growth. Nevertheless, most articles focused on regular shaped (such as triangles and hexagons) 2D layered metal dichalcogenides (LMDs), whereas fractals have received less attention. Therefore, understanding the controlled synthesis of LMDs materials with unique edge structures is highly desired for various potential applications. Here, we report large fractal growth of tin disulfide (SnS2) by atmospheric pressure chemical vapor deposition technique. The edge length of the atomically thin SnS2 fractals range from 5 to 100 µm. Our study shows the morphological evolution from fractal to triangular-like structure during the CVD growth process. To understand this phenomenon, we anticipated that the early phase of the growth mostly occurs via kinetic regulated pathway resulting fractal like structure. As the domains go through numerous relaxation phases throughout the edge diffusion process, the morphology gets more compact or regular, indicating increased thermodynamic control over the growth process. We have also provided a physical model for the growth mechanism of CVD grown SnS2. © 2023