Plasmon-enhanced photoluminescence from MoS monolayer with topological insulator nanoparticle.

Topological insulators (TI), as a kind of fantastic nanomaterial with excellent electrical and optical properties, have attracted particular attention due to the promising applications in optoelectronic devices. Herein, we experimentally demonstrated the interaction between light and molybdenum disulfide (MoS) monolayer with an antimony telluride (SbTe) TI nanoparticle. It was found that photoluminescence (PL) emission and Raman scattering signal can be boosted by 5 and 8 folds in MoS monolayer integrated with the TI nanoparticle, respectively. The measured and simulated dark-field scattering spectra illustrated that the enhancement of light-matter interaction could be derived from the generation of localized surface plasmons on the TI nanoparticle with distinctly boosted electric field. We also found that there exists a redshift of 5 nm for the enhanced PL peak, which could be attributed to the formation of trions in MoS induced by plasmon doping. This work would provide a new pathway for the applications of TI nanoparticles in the optoelectronics, especially light-matter interaction enhancement.