Gap plasmon-enhanced photoluminescence of monolayer MoS2 in hybrid nanostructure**Project supported by the National Natural Science Foundation of China (Grant Nos. 61590932 and 11774333), the Anhui Initiative Project in Quantum Information Technologies, China (Grant No. AHY130300), the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDB24030600), the National Key Research and Development Program of China (Grant No.

Abstract

Monolayer transition-metal dichalcogenides (TMDs) have attracted a lot of attention for their applications in optics and optoelectronics. Molybdenum disulfide (MoS2), as one of those important materials, has been widely investigated due to its direct band gap and photoluminescence (PL) in visible range. Owing to the fact that the monolayer MoS2 suffers low light absorption and emission, surface plasmon polaritons (SPPs) are used to enhance both the excitation and emission efficiencies. Here, we demonstrate that the PL of MoS2 sandwiched between 200-nm-diameter gold nanoparticle (AuNP) and 150-nm-thick gold film is improved by more than 4 times compared with bare MoS2 sample. This study shows that gap plasmons can possess more optical and optoelectronic applications incorporating with many other emerging two-dimensional materials.