| AVS 65th International Symposium & Exhibition | |
| 2D Materials Focus Topic | Thursday Sessions |
| Session 2D+EM+MN+NS-ThA |
| Session: | Novel Quantum Phenomena in 2D Materials |
| Presenter: | Kathleen McCreary, U.S. Naval Research Laboratory |
| Authors: | K.M. McCreary, U.S. Naval Research Laboratory A.T. Hanbicki, U.S. Naval Research Laboratory S.V. Sivaram, U.S. Naval Research Laboratory B.T. Jonker, U.S. Naval Research Laboratory |
| Correspondent: | Click to Email |
We survey a large number of monolayer TMDs to better understand the conditions responsible for various emission characteristics that have been reported in literature. We find that the intensities for both A- and B- peak emission vary widely as a result of sample-to-sample variations. However, a measurable B-peak intensity is evident in all samples. There is a clear linear relationship between the two peak intensities. The emission from the dominant A-peak is commonly several orders of magnitude higher than B-peak emission, resulting in B/A-intensity ratios well below 1%. Yet, as the A-peak intensity decreases, the ratio of B/A monotonically increases, and we observe a B/A ratio up to 30% in monolayer MoS2. The A-excitonic emission is further quenched when MoS2is incorporated into an MoS2/MoSe2heterostructure, where we observe comparable A- and B-peak intensities. We attribute these variations to differences in exciton recombination times, clarifying contradictory reports regarding the accessibility and significance of B-peak emission. Furthermore, we observe a high degree of valley polarization in both B-exciton emission in isolated monolayers and A-exciton emission in heterostructures, consistent with our model detailing the rapid exciton lifetimes in B-emission and van der Waals heterostructures.
Supported by core programs at NRL and the NRL Nanoscience Institute