Exciton trapping in periodic potentials in monolayer transition metal dichalcogenide crystals as defined by in-plane electric fields

Excitons in monolayer transition metal dichalcogenide (TMDC) semiconductors have emerged as a widely studied platform for exploring many-body physics and light-matter interactions. Achieving precise control of exciton confinement will facilitate further advances in the field. In this work, we employ in-plane electric fields to generate a trapping potential for neutral excitons in monolayer MoSe₂. Previous studies have demonstrated the robustness and tunability of this mechanism. Here we examine the behavior of excitons confined in a periodic nanoscale potential. Specifically, we fabricate a patterned metal mesh with a periodicity of several hundred nanometers beneath the MoSe₂ monolayer, separated by a thin hBN layer, which creates a periodic potential landscape for excitons in the monolayer. We have examined the resulting exciton localization through low-temperature optical measurements. We observe discrete and tunable energy splittings of the neutral excitons and trions. We will discuss these results in the context of the trapping potential created by the exciton polarizability in the presence of spatially varying in-plane electric fields.