Because of their atomic-layer thickness, direct band gap, mechanical robustness, and other superior properties, transition metal dichalcogenide (TMDC) monolayers are considered as an attractive alternative to graphene for diverse optoelectronic applications. However, because of the very nature of their atomic-layer thickness, the interaction of light with TMDCs is limited, hindering the overall efficiency for optical applications. Therefore, for TMDCs to become a true candidate as the material of choice for optoelectronics, there is a need for a mechanism that significantly enhances the interaction of light with TMDCs. In this paper, we demonstrate about 30-fold enhancement of the overall photoluminescence emission intensity from a WS2 monolayer, by its coupling to a hyperbolic metamaterial nanoantenna array. This enhancement corresponds to nearly 300-fold enhancement per individual nanoantenna. This overall enhancement is achieved by the combination of enhancing the excitation (absorption) efficiency and enhancing the radiative decay rate. Our result paves the way for the use of TMDCs in diverse optoelectronic applications, ranging from light sources and photodetectors to saturated absorbers and nonlinear media.
Bibliographical noteFunding Information:
We acknowledge funding from the Israeli Ministry of Science and Technology and The Air Force Office of Scientific Research. C.F. is supported by the Carlsberg Foundation as an Internationalization Fellow. Samples were fabricated at the center for nanoscience and nanotechnology of the Hebrew university. We thank Atzmon Vakahi and Sergei Remennik for FIB and STEM measurements.
© 2020 American Chemical Society
- Hyperbolic nanoantenna
- Light-matter interaction
- Nanoscale-cavity quantum electrodynamics
- Purcell factor
- Surface-enhanced Raman scattering
- WS monolayer