Abstract
Raman spectroscopy is a powerful technique to probe structural and doping behaviors of two-dimensional (2D) materials. In MoS2, the always coexisting in-plane (E2g1) and out-of-plane (A1g) vibrational modes are used as reliable fingerprints to distinguish the number of layers, strains, and doping levels. In this work, however, we report an abnormal Raman behavior, i.e., the absence of the A1g mode in cetyltrimethylammonium bromide (CTAB)-intercalated MoS2 superlattice. This unusual behavior is quite different from the softening of the A1g mode induced by surface engineering or electric-field gating. Interestingly, under a strong laser illumination, heating, or mechanical indentation, an A1g peak gradually appears, accompanied by the migration of intercalated CTA+ cations. The abnormal Raman behavior is mainly attributed to the constraint of the out-of-plane vibration due to intercalations and resulting severe electron doping. Our work renews the understanding of Raman spectra of 2D semiconducting materials and sheds light on developing next-generation devices with tunable structures.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
