Low-Cost Plasmonic Platform for Photon-Emission Engineering of Two-Dimensional Semiconductors

Abstract

Although the field of two-dimensional (2D) materials has democratized materials science by making high-quality samples accessible cheaply, due to the atomically thin nature of these systems, an integration with nanostructures is almost always required to obtain a significant optical response. Traditionally, these nanostructures are fabricated via electron beam lithography or focused ion beam milling, which are expensive, and large-area fabrication can be further time-consuming. In order to overcome this problem, we report the integration of 2D semiconductors on a cost-effective and large-area fabricated nanocone platform. We show that the plasmon modes of our nanocone structures lead to photoluminescence enhancement of monolayer ${\text{WSe}}_{2}$ by about eight to ten times compared with the nonplasmonic case, consistent with finite-difference time-domain simulations. Excitation power-dependent measurements reveal that our nanocone platform enables a versatile route to engineering the relative exciton trion contributions to the emission.