Localized Moiré Excitons in Twisted Two-Dimensional Semiconductors

Fabricated from twisted atomically thin transition metal dichalcogenides (TMDs) monolayers, moiré materials show interlayer exciton coupling at localized high symmetry points. Here we investigate the excitation energy of moiré excitons, a quasiparticle consisting of an interlayer bound electron-hole pair, and their dependence on the relative orientation of the layers at these points. By controlling the twist angle between constituent layers, the electronic band structure of these moiré excitons can be manipulated. Using Raman and photoluminescence spectroscopy, we investigate how these interlayer excitons interact through an adjusted twist angle. By studying the Raman-activate vibrational modes at these moiré exciton sites, we hope to gain insight into how these slightly mismatched planes of atoms interact with the moiré material’s electronic and optical properties. These findings could pave the way for future developments in optoelectronic devices, such as tunable light emitters and quantum information technologies, where precise control over excitonic behavior is essential.