Fig. 4: Transfer and characterization of molybdenum disulfide (MoS₂) and MoS₂/graphene heterostructures.

a Averaged Raman spectra of multilayer MoS₂ on the SiO₂/Si growth substrate before transfer (blue) and after transfer to the target wafer (red). The Raman spectra are averages of area scans with 8 × 10 measurements in 1 mm² areas (black rectangle in the photograph of transferred MoS₂) and were normalized to the intensity of the E¹_2g mode. The shaded regions represent the standard deviation of the intensity. The vertical dashed lines indicate the peak positions of the E¹_2g and A_1g modes of the as-grown film before transfer. b Averages of 25 photoluminescence (PL) intensity spectra of pristine (blue) and transferred (red) multilayer MoS₂ with A and B excitonic transitions (shaded areas: standard deviation). The inset magnifies the region from 1.945 to 1.98 eV and shows the Raman modes of bisbenzocyclobutene (BCB), which are superimposed with the optical response of the MoS₂ layer. c Spatially resolved map (left) and histogram (right) of the graphene sheet resistance (R_sh) from terahertz near-field spectroscopy (resolution: 300 μm). The MoS₂/graphene heterostructure in the center (rectangular region) is surrounded by graphene, both resting on BCB. d Raman and PL spectroscopy of the MoS₂/graphene heterostructure, measured in a 1 × 1 mm² region on the same sample as in panel (c) (white rectangle). The Raman peak positions indicate the presence of both MoS₂ (E¹_2g and A_1g peaks) and graphene (2D peak position (ω_2D) and the respective full-width at half-maximum (\({\it{\Gamma}}_{2{\mathrm{D}},{\mathrm{MoS}}_{2}/{\mathrm{gr}}}\)). The averaged PL spectrum (bottom right) shows the A and B excitonic transitions of MoS₂ and the superimposed Raman modes of BCB (shaded area: standard deviation).