Synthesis of Large-Area MoSe2 Monolayer Film for Surface-Enhanced Raman Scattering Analysis

Ultrathin two-dimensional transition metal dichalcogenides represent a promising new class of materials with surface-enhanced Raman scattering (SERS) activities. Previous work mainly focused on the SERS effects of transition metal dichalcogenide crystals with sizes of micrometer scale. The enhancement effect is usually nonuniform on the SERS substrates. In this paper, we report a chemical vapor deposition method for the preparation of centimeter-scale MoSe2 films with uniform and high SERS activity. The molybdenum precursors are supplied in a face-to-face manner from a silica gel plate to the growth substrate, which guarantees uniform nucleation and growth of the monolayer MoSe2. We demonstrate that the monolayer MoSe2 film has strong SERS effect, which can be attributed to charge transfer between MoSe2 and the probe molecules. The detection limit of Rhodamine B on monolayer MoSe2 is determined to be 10(-7) mol/L, and the Raman enhancement factor is estimated to be 5.58 x 10(4). Due to its atomic uniformity and chemical stability, the MoSe2 film can serve as an ideal two-dimensional SERS material for detection of various molecules.

Automated summary

A method for preparing centimeter-scale MoSe2 films with uniform and high SERS activity is reported, demonstrating the strong SERS effect of monolayer MoSe2 film attributed to charge transfer between MoSe2 and probe molecules. Due to its atomic uniformity and chemical stability, MoSe2 film can serve as an ideal two-dimensional SERS material for detection of various molecules.