2010/04/14 by Changgu Lee, Hugen Yan, Louis E. Brus +3 · 2 citations
Materials Science · Physics and Astronomy · #2D Materials and Applications #Graphene research and applications #Lattice (music) #Lattice vibration #Molybdenum disulfide #Normal mode #Organic and Molecular Conductors Research #Raman spectroscopy #Substrate (aquarium) #Vibration #Work (physics) #cond-mat.mtrl-sci #van der Waals force
paper · pdf · doi:10.1021/nn1003937
published as ACS Nano 4, 2695 (2010) · 14 pages, 4 figures
openalex publication_date 2010/04/14 · arxiv created 2010/05/14 · arxiv updated 2010/11/16 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Molybdenum disulfide (MoS(2)) of single- and few-layer thickness was exfoliated on SiO(2)/Si substrate and characterized by Raman spectroscopy. The number of S-Mo-S layers of the samples was independently determined by contact-mode atomic force microscopy. Two Raman modes, E(1)(2g) and A(1g), exhibited sensitive thickness dependence, with the frequency of the former decreasing and that of the latter increasing with thickness. The results provide a convenient and reliable means for determining layer thickness with atomic-level precision. The opposite direction of the frequency shifts, which cannot be explained solely by van der Waals interlayer coupling, is attributed to Coulombic interactions and possible stacking-induced changes of the intralayer bonding. This work exemplifies the evolution of structural parameters in layered materials in changing from the three-dimensional to the two-dimensional regime.