Plasmonic Hybrids of MoS and 10-nm Nanogap Arrays for Photoluminescence Enhancement.

Monolayer MoS has attracted tremendous interest, in recent years, due to its novel physical properties and applications in optoelectronic and photonic devices. However, the nature of the atomic-thin thickness of monolayer MoS limits its optical absorption and emission, thereby hindering its optoelectronic applications. Hybridizing MoS by plasmonic nanostructures is a critical route to enhance its photoluminescence. In this work, the hybrid nanostructure has been proposed by transferring the monolayer MoS onto the surface of 10-nm-wide gold nanogap arrays fabricated using the shadow deposition method. By taking advantage of the localized surface plasmon resonance arising in the nanogaps, a photoluminescence enhancement of ~20-fold was achieved through adjusting the length of nanogaps. Our results demonstrate the feasibility of a giant photoluminescence enhancement for this hybrid of MoS/10-nm nanogap arrays, promising its further applications in photodetectors, sensors, and emitters.