Abstract
Interlayer coupling plays essential roles in the quantum transport, polaritonic, and electrochemical properties of stacked van der Waals (vdW) materials. In this work, we report the unconventional interlayer coupling in vdW heterostructures (HSs) by utilizing an emerging 2D material, Janus transition metal dichalcogenides (TMDs). In contrast to conventional TMDs, monolayer Janus TMDs have two different chalcogen layers sandwiching the transition metal and thus exhibit broken mirror symmetry and an intrinsic vertical dipole moment. Such a broken symmetry is found to strongly enhance the vdW interlayer coupling by as much as 13.2% when forming MoSSe/MoS2 HS as compared to the pristine MoS2 counterparts. Our noncontact ultralow-frequency Raman probe, linear chain model, and density functional theory calculations confirm the enhancement and reveal the origins as charge redistribution in Janus MoSSe and reduced interlayer distance. Our results uncover the potential of tuning interlayer coupling strength through Janus heterostacking.
| Original language | English |
|---|---|
| Pages (from-to) | 17499-17507 |
| Number of pages | 9 |
| Journal | Journal of the American Chemical Society |
| Volume | 142 |
| Issue number | 41 |
| DOIs | |
| State | Published - Oct 14 2020 |
Bibliographical note
Publisher Copyright:© 2020 American Chemical Society.
Funding
K.Z. acknowledges the support from Milton and Albertha Langdon Memorial Graduate Fellowship. The early stage development of Janus structures (Y.G.) was supported by the Air Force Office of Scientific Research under the MURI-FATE program, grant number FA9550-15-1-0514, the later stage of the Janus structure conversion and characterization (Y.G.) was support by U.S. Department of Energy, Office of Science, Basic Energy Sciences, award number DESC0020042. The CVD MoS2 materials were synthesis by Q.J. with the support from the STC Center for Integrated Quantum Materials, National Science Foundation, grant number DMR-1231319. A.-Y. L. assisted the setup to convert Janus materials and characterizations and was supported by the U.S. Army Research Office through the Institute for Soldier Nanotechnologies at MIT, under contract number W911NF-18-2-0048. C.S. collected the STEM characterization of Janus materials and was support by U.S. Army Research Office under grant number W911NF-18-1-0431. H.W. and X.Q. acknowledge the support from the National Science Foundation under grant number DMR-1753054. S.F. is supported by a Rutgers Center for Material Theory Distinguished Postdoctoral Fellowship. E.K. acknowledges the support from STC Center for Integrated Quantum Materials, National Science Foundation, grant number DMR-1231319. S.H. acknowledges the support from the National Science Foundation under grant number ECCS-1943895.
| Funders | Funder number |
|---|---|
| Institute for Soldier Nanotechnologies | DMR-1753054, W911NF-18-1-0431, ECCS-1943895, W911NF-18-2-0048 |
| Milton and Albertha Langdon Memorial | |
| STC Center for Integrated Quantum Materials | |
| National Science Foundation | 1943895, DMR-1231319 |
| U.S. Department of Energy | |
| Air Force Office of Scientific Research | FA9550-15-1-0514 |
| Army Research Office | |
| Office of Science | |
| Basic Energy Sciences | DESC0020042 |