Journal/Book/Conference Title Title
Physical Review B
We have investigated the vibrational properties of van der Waals heterostructures of monolayer transition metal dichalcogenides (TMDs), specifically MoS2/WSe2 and MoSe2/MoS2 heterobilayers and twisted MoS2 bilayers, by means of ultralow-frequency Raman spectroscopy. We discovered Raman features (at 30–40 cm−1) that arise from the layer-breathing mode (LBM) vibration between the two incommensurate TMD monolayers in these structures. The LBM Raman intensity correlates strongly with the suppression of photoluminescence that arises from interlayer charge transfer. The LBM is generated only in bilayer areas with direct layer-layer contact and an atomically clean interface. Its frequency also evolves systematically with the relative orientation between the two layers. Our research demonstrates that the LBM can serve as a sensitive probe to the interface environment and interlayer interactions in van der Waals materials.
Department of Physics
Original Publication Date
DOI of published version
UNI ScholarWorks, University of Northern Iowa, Rod Library
©2015 C.H. Lui, Zhipeng Ye, Chao Ji, Kuan-Chang Chiu, Cheng-Tse Chou, Rond I. Andersen, Casie Means-Shively, Heidi Anderson, Jenn-Ming Wu, Tim Kidd, Yi-Hsien Lee, and Rui He. The copyright holder has granted permission for posting
Lui, C. H.; Ye, Zhipeng; Ji, Chao; Chiu, Kuan-Chang; Chou, Cheng-Tse; Andersen, Trond I.; Means-Shively, Casie; Anderson, Heidi; Wu, Jenn-Ming; Kidd, Tim; Lee, Yi-Hsien; and He, Rui, "Observation of Interlayer Phonon Modes in van der Waals Heterostructures" (2015). Faculty Publications. 3.