title: Quantitative Raman spectrum and reliable thickness identification for atomic layers on insulating substrates.
abstract: We demonstrate the possibility in quantifying the Raman intensities for both specimen and substrate layers in a common stacked experimental configuration and, consequently, propose a general and rapid thickness identification technique for atomic-scale layers on dielectric substrates. Unprecedentedly wide-range Raman data for atomically flat MoS(2) flakes are collected to compare with theoretical models. We reveal that all intensity features can be accurately captured when including optical interference effect. Surprisingly, we find that even freely suspended chalcogenide few-layer flakes have a stronger Raman response than that from the bulk phase. Importantly, despite the oscillating intensity of specimen spectrum versus thickness, the substrate weighted spectral intensity becomes monotonic. Combined with its sensitivity to specimen thickness, we suggest this quantity can be used to rapidly determine the accurate thickness for atomic layers.
authors: WPI Center for Materials Nanoarchitechtonics (WPI-MANA), National Institute for Materials Science, Tsukuba, Ibaraki 305-0044, Japan. li.songlin@nims.go.jp
authors: Song-Lin
authors: SL
authors: Li
authors: Hisao
authors: H
authors: Miyazaki
authors: Haisheng
authors: H
authors: Song
authors: Hiromi
authors: H
authors: Kuramochi
authors: Shu
authors: S
authors: Nakaharai
authors: Kazuhito
authors: K
authors: Tsukagoshi
mesh_terms: D008422:Materials Testing / Q000379:methods*; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure*; D013059:Spectrum Analysis, Raman / Q000379:methods*