Enhanced contrast to circularly polarized excitation in large-area continuous MoS2 monolayer coupled to plasmonic spiral arrays

Abstract

Most applications in optoelectronics that utilize two-dimensional transition metal dichalcogenides (TMDs) are currently limited to micrometer sizes, making the scalability of these devices practically significant. This study investigates the interaction between plasmonic arrays featuring Archimedes spiral patterns and large-area MoS2 films measuring 1 cm2. Despite the presence of defect states in these large-area MoS2 monolayers, we recorded a maximum 40% contrast in photoluminescence when comparing left and right circularly polarized excitation, with a degree of polarization of 0.3 ± 0.1, considering positional variation using a wide-field excitation. We found that bringing the spirals closer together enhances the contrast of the degree of polarization in the absence of the diffractive lattice mode. Our study demonstrates the potential of large-area TMD-based devices and underscores the importance of improving or engineering material quality to achieve device performances comparable to those based on micrometer-sized TMD flakes.