| AVS 62nd International Symposium & Exhibition | |
| 2D Materials Focus Topic | Thursday Sessions |
| Session 2D-ThP |
| Session: | 2D Materials Focus Topic Poster Session |
| Presenter: | Iori Tanabe, University of Nebraska - Lincoln |
| Authors: | I. Tanabe, University of Nebraska - Lincoln D. Le, University of Central Florida A.V. Barinov, Sincrotrone Trieste, Italy E. Preciado, University of California - Riverside M. Isarraraz, University of California - Riverside T. Komesu, University of Nebraska - Lincoln L. Bartels, University of California - Riverside T.S. Rahman, University of Central Florida P.A. Dowben, University of Nebraska - Lincoln |
| Correspondent: | Click to Email |
WSe2 and the related metal dichalcogenides MX2 (with M = V, Mo, W, Ta and X = S, Se, Te) are layered structures that in each plane consist of a hexagonal honeycomb lattice reminiscent of graphene or graphite. WSe2 is a semiconductor, rather than a gapless semiconductor (like graphene) or semimetal, and is expected to have applications for new spintronic devices where spin-orbit coupling might play a valuable role. Here, we used high-resolution angle resolved photoemission spectroscopy (ARPES) and inverse photoemission spectroscopy (IPES) to map out the electronic band structure of single-layer WSe2. The splitting of the top of the valence band due to spin-orbit coupling was found to be 513±10 meV, far larger than that for MoS2. As expected the top of the valence band is at K. Overall, density functional theory (DFT) calculations were in excellent agreement with the ARPES results, and we have verified that the few discrepancies between theory and experiment were not due to the effect of strain. Cobalt on WSe2 is seen to have a very complex interface, with strong interactions, as seen in the changes to the experimental electronic structure. Without the complexity of a metal adlayer, WSe2 is seen to be routinely Se rich and should thus be reliably p-type.