Observation of Layer-Breathing Mode Vibrations in Few-Layer Graphene through Combination Raman Scattering

Abstract

We report the observation of layer-breathing mode (LBM) vibrations in few-layer graphene (FLG) samples of thickness from two to six layers, exhibiting both Bernal (AB) and rhombohedral (ABC) stacking order. The LBM vibrations are identified using a Raman combination band lying around 1720 cm(-1). From double resonance theory, we assign the feature as the LO+ZO' combination mode of the out-of-plane LBM (ZO') and the in-plane longitudinal optical mode (LO). The LOZO' Raman band is found to exhibit multiple peaks with a unique line shape for each layer thickness and stacking order. These complex line shapes of the LOZO'-mode arise both from the material-dependent selection of different phonons in the double-resonance Raman process and from the detailed structure of the different branches of LBM in FLG.

Configuration-enriched magneto-electronic spectra of AAB-stacked trilayer graphene

“…The essential electronic properties can be drastically changed by the layer number [35][36][37], stacking configuration [37][38][39][40][41][42], magnetic field [43,44], electric field [45][46][47], dopping [48,49], mechanical strain [50][51][52], and temperature variation [53,54]. Few-and multi-layer graphenes have been successfully produced by experimental methods such as exfoliation of highly orientated pyrolytic graphite [55][56][57][58], metalorganic chemical vapour deposition (MOCVD) [61][62][63][64][65][66], chemical and electrochemical reduction of graphene oxide [67][68][69], and arc discharge [70,71]. There exist important stacking configurations, including AAB [57,58,69], ABC [59,60,[66][67][68][69], AAA …”

“…Few-and multi-layer graphenes have been successfully produced by experimental methods such as exfoliation of highly orientated pyrolytic graphite [55][56][57][58], metalorganic chemical vapour deposition (MOCVD) [61][62][63][64][65][66], chemical and electrochemical reduction of graphene oxide [67][68][69], and arc discharge [70,71]. There exist important stacking configurations, including AAB [57,58,69], ABC [59,60,[66][67][68][69], AAA [62,63], ABA [60,61,66,69], and twisted [62,69] and turbostratic ones [64]. The interlayer atomic interactions and stacking configurations induce the rich electronic properties of graphene.…”

Low-Frequency Interlayer Breathing Modes in Few-Layer Black Phosphorus

“…With the surge of interest in two-dimensional (2D) materials (such as graphene and transition metal dichalcogenides (TMDs)) 23,24 , BP has become a new attraction since 2014 because it bridges the gap between graphene and TMDs, and offers the best trade-off between mobility and on-off ratio 3 . Moreover, the unique anisotropic puckered honeycomb lattice of BP leads to many novel in-plane anisotropic properties, which could lead to more applications based on BP 3,9,25,26 .Phonon behaviors play an important role in the diverse properties of materials 27 , which has been intensively studied in vdW layered materials, such as graphene and TMDs [28][29][30][31][32][33][34][35] . Raman spectroscopy is a powerful non-destructive tool to investigate the phonons and their coupling to electrons, and has been successfully applied to vdW layered materials [36][37][38][39][40] .…”

Resonant Raman spectroscopy of twisted multilayer graphene

“…The Raman spectrum of graphite and MLG consists of two fundamentally different sets of peaks. Those, such as D, G and 2D, present also in SLG, and due to in-plane vibrations 14,16,17 , and others, such as the shear (C) modes 18 and the layer breathing modes [19][20][21] , due to the relative motions of the planes themselves, either perpendicular or parallel to their normal. The G peak corresponds to the high-frequency E 2g phonon at G. The D peak is due to the breathing modes of six-atom rings and requires a defect for its activation 16,[22][23][24] .…”