Ultrathin platelet antennas mediated light-matter interaction in monolayer MoS₂

Monolayer MoS₂ is an emerging two-dimensional semiconductor that has seen wide applications in optoelectronic and light-emitting devices. Here we report on the antenna-enhanced spontaneous emission of monolayer MoS₂, which has weak absorbance and low intrinsic quantum yield. The ultrathin silver platelet antennas we use can both increase the absorption cross-section and improve the transmission efficiency via controlling the optical field at nanometer scale. Experimental results indicate the photoluminescence enhancement can reach 4 times, which is also supported by numerical analysis of both excitation and emission processes with respect to the thickness of spacer layer. This ultrathin structure can facilitate the development of on-chip emitters and valley-based devices, especially in cases of large area sample or flexible substrate.