Synthesis and Photoluminescence Properties of MoS2/Graphene Hetero-Structure by Liquid Phase Exfoliation

Synthesis of MoS2/Graphene hetero-structure in single stage, liquid-phase exfoliation in 7:3 isopropyl alcohol /water mixture and its consequences on the photoluminescence behavior of MoS2 have been studied. Thus synthesized hetero-structure was characterized using UV-visible, micro-Raman spectroscopy, Transmission electron microscopy(TEM), and Dynamic Light Scattering (DLS) analysis. UV-Visible and micro-Raman analysis confirm improved exfoliation to the level of monolayer hetero-structure. The photophysical properties of the hetero-structure were analyzed using steady state and time resolved luminescence techniques. An enhanced photoluminescence observed in the case of hetero-structure probably due to increase in the defect sites or reduction in the rate of non-radiative decay upon formation of sandwiched hetero-structure. Applications of this hetero-structure for fluorescence live cell imaging carried out and the hetero-structure demonstrated a better luminescence contrast compared to its individual counterpart MoS2 in phosphate buffered saline (PBS).