Extended Data Fig. 2: Trion-free photoluminescence spectra at room temperature.
From: Filtering the photoluminescence spectra of atomically thin semiconductors with graphene
PL spectra of BN-capped TMD/graphene heterostructures compared to those of a nearby BN-capped TMD reference, all recorded in ambient air in the linear regime under continuous-wave laser excitation at 2.33 eV. The X0 PL lines are symmetric in the TMD/graphene heterostructures whereas they exhibit a lower-energy shoulder arising predominantly from trions (X⋆) in the TMD references. The scaling factors allow estimating the large room temperature PL quenching factors that strongly contrast with the low X0 PL quenching factors observed at cryogenic temperatures (see main text and supplementary Table 1). The X0 lines are slightly redshifted in TMD/graphene, as discussed in the main text and supplementary Section 4. The red lines are multi-Lorentzian fits to the data, with their different components shown with grey dashed lines. Hot luminescence from excited excitonic states (for example, X\({}_{2{\rm{s}}}^{0}\) and B excitons) is clearly visible in MoS2/graphene and MoSe2/graphene. This figure appears as supplementary Fig. 7 in the supplementary information file.
