The shapes of synthesized two-dimensional materials

Abstract

The shapes of as-grown/as-etched two-dimensional (2D) islands are the most recognizable features of the chemical vapor deposition (CVD) process which reveal a lot of information about the chemical environment of growth/etching, the effect of the substrate and the growth/etching kinetics. Here, we summarize experimentally observed shapes of CVD-grown 2D materials from previous reports, theoretical understanding on the corresponding mechanisms and the simulations of the corresponding growth/etching processes. Each part of the review article is organized by combining the fundamental principles that govern the shapes of crystals during growth/etching and the related experimental observations to facilitate the readers to read and understand the content. The content of the review includes attachment-limited 2D materials growth, diffusion-limited 2D materials growth (both with and without influence of the substrate), etching and merging of 2D materials with and without considering the effect of the substrate. We also discuss growth and etching of multilayered 2D islands during CVD—a topic still under development. We wish this review will also guide the audience to understand the kinetics of 2D materials growth and to improve controllable synthesis of various 2D materials.