Atomically thin transition metal dichalcogenides (TMDs) have recently attracted great attention since the unique and fascinating physical properties have been found in various TMDs, implying potential applications in next-generation devices. The progress towards developing new functional and high-performance devices based on TMDs, however, is limited by the difficulty of producing large-area monolayer TMDs due to a lack of knowledge of the growth processes of monolayer TMDs. In this work, we have investigated the growth processes of monolayer WS2 crystals using a thermal chemical vapor deposition method, in which the growth conditions were adjusted in a systematic manner. It was found that, after forming WO3-WS2 core-shell nanoparticles as nucleation sites on a substrate, the growth of three-dimensional WS2 islands proceeds by ripening and crystallization processes. Lateral growth of monolayer WS2 crystals subsequently occurs by surface diffusion process of adatoms. Our results provide understanding of the growth processes of monolayer WS2 by using chemical vapor deposition methods.
@article{arxiv.1809.00331,
title = {Surface-diffusion-limited growth of atomically thin WS2 crystals from core-shell nuclei},
author = {Sunghwan Jo and Jin-Woo Jung and Jaeyoung Baik and Jang-Won Kang and Il-Kyu Park and Tae-Sung Bae and Hee-Suk Chung and Chang-Hee Cho},
journal= {arXiv preprint arXiv:1809.00331},
year = {2019}
}