Position-dependent valley polarization and valley coherence of WS2 monolayers

Two-Dimensional Transition Metal Dichalcogenides (2D TMDs) have been widely investigated in the past years. These atomically thin semiconductors possess interesting optical properties. In the monolayer limit, they have a direct bandgap in the visible wavelength range, where electron-hole pairs form stable excitons even at room-temperature. The selection rules for transitions in the non-degenerate TMDs valleys make it possible to selectively address each valley using circularly polarized light. Therefore, studying the (circular) polarization-resolved photoluminescence is essential for understanding the underlying physics in the TMDs valleys.