| AVS 65th International Symposium & Exhibition | |
| Nanometer-scale Science and Technology Division | Thursday Sessions |
| Session NS-ThP |
| Session: | Nanometer-scale Science and Technology Division Poster Session |
| Presenter: | Hsun-Jen Chuang, Naval Research Laboratory |
| Authors: | H.-J. Chuang, Naval Research Laboratory A.T. Hanbicki, Naval Research Laboratory M. Rosenberger, Naval Research Laboratory C.S. Hellberg, Naval Research Laboratory S.V. Sivaram, Naval Research Laboratory K.M. McCreary, Naval Research Laboratory I. Mazin, Naval Research Laboratory B.T. Jonker, Naval Research Laboratory |
| Correspondent: | Click to Email |
Indirect transition and opposite circular polarization of Interlayer Exciton in a MoSe2/WSe2 van der Waals Heterostructure
Hsun-Jen Chuang, A.T. Hanbicki, M.R. Rosenberger, C. Stephen Hellberg, S.V. Sivaram, K.M. McCreary, I.I. Mazin, and B.T. Jonker
Naval Research Laboratory, Washington, DC 20375
An emerging class of heterostructures involves monolayer semiconductors such as many of the transition metal dichalcogenides (TMDs) which can be combined to form van der Waals heterostructures (vdWHs). One unique new heterostructure property is an interlayer exciton (ILE), a spatially indirect, electron-hole pair with the electron in one TMD layer and the hole in the other.
In this report [1], we use state-of-the-art preparation techniques [2] to create MoSe2/WSe2 heterostructures encapsulated in hBN. We observe ILE emission around 1.35 eV at room temperature and resolve this emission into two distinct peaks (ILE1 and ILE2) separated by 24 meV at zero field at 5 K. Furthermore, we demonstrate that the two emission peaks have opposite circular polarizations with up to +20% for the ILE1 and -40% for ILE2 when excited by circularly polarized light. Ab initio calculations provide an explanation of this unique and potentially useful property and indicate that it is a result of the indirect character of both electronic transitions. These peaks are double indirect excitons. i.e. indirect in both real and reciprocal space, split by relativistic effects.
This work was supported by core programs at NRL and the NRL Nanoscience Institute, and by the Air Force Office of Scientific Research #AOARD 14IOA018-134141. This work was also supported in part by a grant of computer time from the DoD High Performance Computing Modernization Program at the U.S. Army Research Laboratory Supercomputing Resource Center.
[1] Hanbicki, Aubrey T., Hsun-Jen Chuang, et al. "Double Indirect Interlayer Exciton in a MoSe2/WSe2 van der Waals Heterostructure." ACS Nano 12 (5) 2018: 4719-4726.
[2] Matthew R Rosenberger, Hsun-Jen Chuang, et al. “Nano-“Squeegee” for the Creation of Clean 2D Material Interfaces” ACS applied materials & interfaces 10 (12) 2018: 10379-10387