期刊
NANOTECHNOLOGY
卷 30, 期 27, 页码 -出版社
IOP Publishing Ltd
DOI: 10.1088/1361-6528/ab11ad
关键词
atomic force microscopy; layer-by-layer thinning; molybdenum disulfide; nanoparticles; laser irradiation
资金
- Basic Science Research Program through the National Research Foundation of Korea (NRF) - Ministry of Science, ICT and Future Planning [NRF-2017R1A2B4009651]
Layer-by-layer thinning of molybdenum disulfide (MoS2) via laser irradiation was examined using Raman spectroscopy and atomic force microscopy. In particular, the effects of number of layers, laser conditions, and substrate were systematically identified. The results demonstrated the presence of nanoparticles on the MoS2 at sufficient laser treatment conditions prior to layer-by-layer thinning The volume of nanoparticles was found to increase and then decrease as the number of MoS2 layers increased; the non-monotonic trend was ascribed to changes in the thermal conductivity of the film and interfacial thermal conductance between the film and substrate with number of layers. Moreover, the volume of nanoparticles was found to increase as the magnification of the objective lens decreased and as laser power and exposure time increased, which was attributed to changes in the power density with laser conditions. The effect of substrate on nanoparticle formation and layer-by-layer thinning was investigated through a comparison of freestanding and substrate-supported MoS2 subjected to laser irradiation; it was illustrated that freestanding films were thinned at lower laser powers than substrate-supported films, which highlighted the function of the substrate as a heat sink. For conditions that elicited thinning, it was shown that the thinned areas exhibited triangular shapes, which suggested anisotropic etching behavior where the lattice of the basal plane was preferentially thinned along the zigzag direction terminated by an Mo- or S-edge. High-resolution transmission electron microscopy of freestanding MoS2 revealed the presence of a 2 nm thick amorphous region around the laser-treated region, which suggested that the crystalline structure of laser-treated MoS2 remained largely intact after the thinning process. In all, the conclusions from this work provide useful insight into the progression of laser thinning of MoS2, thereby enabling more effective methods for the development of MoS2 devices via laser irradiation.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据