Themed collection Editor’s Choice: Optical Spectroscopy of 2D materials

Raman spectroscopy continues to stimulate the explorations on different types of layered materials.

Anomalous lattice vibrations are observed in CVD-grown monolayer MoS₂ when rotating the sample and using the linear polarization incident light.

Twisted WSe₂ bilayers exhibit hybridized K–Λ excitons with flat moiré bands, which become visible through phonon-assisted photoluminescence.

The orientation of graphene contributed to anisotropic reinforcement, since swelling was restrained in the in-plane direction. The Raman study of the 2D band shift of GNPs under biaxial strain revealed the effective biaxial modulus of graphene.

Experimental and theoretical investigation of true axial stress transfer on regular-exfoliated-graphene micro-ribbons which are aligned to the loading direction.

(a) STM image of a graphite (G) substrate after the Si deposition at RT. (b) Stable configuration of a silicene nanosheet intercalated under the outmost G layer and (c) this outmost G layer distribution of the tensile strain.

Time-resolved spontaneous Raman experiments on 7-AGNRs show the presence of a long lived excitonic dark state together with short and long lived trap states.

The 2D mode of graphene exhibits significant frequency discrepancies between its Stokes and anti-Stokes components, making it possible to probe the nonlinear phonon dispersion of the iTO branch near K.

The concurrent analysis of the morphological and optical properties demonstrates that TEPL is a unique tool to study 2D materials at the nanoscale.

We demonstrate the remote excitation and detection of surface-enhanced Raman scattering (SERS) from graphene using a silver nanowire as a plasmonic waveguide.

Modification of local exciton emission in monolayer MoS₂ by chemical treatments is spatially uneven as revealed by near field imaging.

Azimuthal-dependence reflectance difference microscopy was developed to visualize and characterize the optical anisotropy of low-symmetry 2D materials.

In this article, we present the results of a gap-plasmon tip-enhanced Raman scattering study of MoS₂ monolayers deposited on a periodic array of Au nanostructures on a silicon substrate forming a two dimensional (2D) crystal/plasmonic heterostructure.

Optical forces are used for trapping, characterization, and positioning of layered materials (hBN, MoS₂, and WS₂) obtained by liquid phase exfoliation.

A simple model is developed to reveal the stacking dependence of Raman intensities of interlayer vibrations in 2D materials.

Tunable plasmon–trion and plasmon–exciton resonance energy transfer from a single Au nanotriangle (AuNT) to monolayer MoS₂ are demonstrated.

We present a comprehensive optical study of thin flakes of tungsten disulfide (WS₂) with thickness ranging from mono- to octalayer and in the bulk limit.

The intrinsic Raman signature and phonon dispersion of mono- and few-layer BN have been revealed by both experiment and simulation.

Spatial and spectral maps of excitons, trions and localized defect-bound excitons in monolayer WS₂ are revealed by near-field imaging.