1. A real-time Raman spectroscopy study of the dynamics of laser-thinning of MoS2 flakes to monolayers
- Author
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Enyao Gu, Qiyuan Wang, Youwei Zhang, Chunxiao Cong, Laigui Hu, Pengfei Tian, Ran Liu, Shi-Li Zhang, and Zhi-Jun Qiu
- Subjects
Physics ,QC1-999 - Abstract
Transition metal dichalcogenides (TMDCs) in monolayer form have attracted a great deal of attention for electronic and optical applications. Compared to mechanical exfoliation and chemical synthesis, laser thinning is a novel and unique “on-demand” approach to fabricate monolayers or pattern desired shapes with high controllability and reproducibility. Its successful demonstration motivates a further exploration of the dynamic behaviour of this local thinning process. Here, we present an in-situ study of void formation by laser irradiation with the assistance of temporal Raman evolution. In the analysis of time-dependent Raman intensity, an empirical formula relating void size to laser power and exposure time is established. Void in thinner MoS2 flakes grows faster than in thicker ones as a result of reduced sublimation temperature in the two-dimensional (2D) materials. Our study provides useful insights into the laser-thinning dynamics of 2D TMDCs and guidelines for an effective control over the void formation.
- Published
- 2017
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