Integration of topological insulator nanogap with atomic single layer for boosting photoluminescence

As a new class of nanomaterials, topological insulators with the Dirac surface conducting state and insulating bulk state offer a promising platform for plasmonics with breaking through the frequency and integration limitation of traditional materials. The combination of topological insulators with atomic-layer materials will be significant for the realization of integrated plasmonic functional devices. Herein, we experimentally report the plasmon-enhanced photoluminescence (PL) emission behavior of molybdenum disulfide (MoS₂) single layer integrated with an antimony telluride (Sb₂Te₃) topological insulator nanogap. It is found that the PL response of MoS₂ on the nanogap is dependent on the polarization of incident light. The MoS₂ PL intensity can be distinctly improved with plasmonic excitation on Sb₂Te₃ nanogap. These results will contribute to exploring plasmonic behaviors of topological insulators and their applications in enhanced light-matter interaction for nanoscale light emission and harvesting devices.