Spatial variations in the optical phonon characteristics of both WS2 and hBN reveal that the bubbles are formed at the interface between the top hBN layer and the underlying WS2 monolayer. The presence of the hBN bubbles results in a relatively higher electron density of the underlying WS2 than ...
The moiré periodic potentials in t2LM make twist angle (θ) dependent moiré phonons be observed, which can be used to probe the phonon dispersion curve of monolayer MoS2. We take graphene/MoS2 and WS2/hBN vdWHs as examples to demonstrate how to probe the interfacial coupling in vdWHs by ...
Figure3compares the calculated Raman spectrum of three different monolayer transition metal dichalcogenides (TMDs), namely MoSe2, MoSSe and MoS2, with the experimental data extracted from ref.35. For all three monolayers, a good agreement is observed both for the peak positions and relative amplitude...
When the laser energy is such that the scattered photons have energy close to that of the WSe2 excitons, the resonantly enhanced Raman signal enables the characterization of even one monolayer-thick hBN. We are able to explain the signal using transfer matrix method simulations of SPhP ...
In addition, we performed a detailed analysis of the anharmonic effect in the hBN/monolayer graphene/hBN heterostructure based on the behaviour of the full-width at half maximum of the G mode with increasing electric power: a non-monotonic trend, leading to the key of approximation of the ...
A large monolayer WSe22 flake was first exfoliated onto PDMS. The substrate was mounted on a rotation stage. Partial transfer of the monolayer WSe22, rotation of the substrate by 60°, alignment of the flakes, and transfer again leads to an artificial 2H-phase bilayer WSe22. The MoSe22/...
The surface of hBN is atomically smooth without dangling bonds and charge traps and it has optical phonon modes [1,2,5]. It has a band gap of 5.955 eV and an exciton binding energy of about 130 meV [8,9]. Regarding calculations, the high band gap of hBN is direct for a monolayer ...
5. Conclusions In conclusion, mechanical exfoliation of ZrX2 (X = S, Se) from bulk to the monolayer was reported for the first time and we studied the dimensionality dependence of the Raman spectra in ambient conditions. Raman spectra were observed down to two layers for ZrS2 and to five ...
This band is composed of several bands for graphite and few layers graphene, but has a Lorentzian shape for monolayer graphene and disordered graphite in which stacking in the c direction is not like in graphite [1,59]. Its intensity, compared to the G band can vary from 3 to 1/3 from...