micro-focused ARPES study of electronic structure in Janus monolayer transition metal dichalcogenides

Janus monolayer transition metal dichalcogenides (TMDs) represent a novel class of 2D materials [1,2]. In Janus structures, one side (top or bottom side) of the chalcogen atomic layer within the TMD is substituted with a different chalcogen element. This distinctive configuration induces an out-of-plane electronic polarization, leading to several unique physical properties not observed in usual monolayer TMDs [1]. In our study, we utilized micro-focused angle-resolved photoemission spectroscopy (micro-ARPES)[3] on a Janus monolayer WSeS to examine the modification of the electronic band structure resulting from the substitution of the top selenium atomic layer with sulfur. The Janus monolayer WSeS was synthesized using the plasma treatment [4] on a mechanically exfoliated monolayer WSe₂ sample which was specially prepared for micro-ARPES measurement [5], while being continuously monitored with photoluminescence (PL). We successfully obtained the clear ARPES images on both monolayer WSe₂ and WSeS. Our results reveal that the substitution of the selenium atomic layer with a sulfur atomic layer results in a momentum shift of the K-valley due to in-plane lattice shrinkage, as well as a notable variation of the band structure around the Γ-point. These observations are basically in good agreement with the first-principles band calculations, indicating the emergence of electronic bands peculiar to the Janus compound.

[1] A.-Y. Lu, et al., Nat. Nanotechnol. 12, 744 (2017).

[2] J. Zhang, et al., ACS Nano 11, 8192 (2017).

[3] M. Kitamura et al., Rev. Sci. Instrum. 93, 033906 (2022).

[4] D. B. Trivedi et al., Adv. Mater. 32, 2006320 (2020).

[5] S. Masubuchi et al., Sci. Rep. 12, 10936 (2022).

*This research was partly supported by a CREST project (Grants No. JP-MJCR15F3, No. JPMJCR16F2, No. JPMJCR18T1, and No. JPMJCR20B4) from the Japan Science and Technology Agency (JST) and Japan Society for the Promotion of Science KAKENHI (Grants-in-Aid for Scienti?c Research) (Grants No. JP20H00127, No. JP20H00354, No. JP20H01834, No. JP21H05232, No. JP21H05233, No. JP21H05234, No. JP21H05235, and No.JP21H05236) and KEK-PF (Proposal No. 2018S2-001, No. 2021S2-001, and No. 2021G141).

About APS

The American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics.

Headquarters 1 Physics Ellipse, College Park, MD 20740-3844 (301) 209-3200
Editorial Office 100 Motor Pkwy, Suite 110, Hauppauge, NY 11788 (631) 591-4000
Office of Public Affairs 529 14th St NW, Suite 1050, Washington, D.C. 20045-2001 (202) 662-8700

Bulletin of the American Physical Society

2024 APS March Meeting

Monday–Friday, March 4–8, 2024; Minneapolis & Virtual

Session S64: Characterizations of 2D Materials by Photoemission and Scanning Probe

Abstract: S64.00001 : micro-focused ARPES study of electronic structure in Janus monolayer transition metal dichalcogenides*

Presenter:

Authors:

Follow Us

Engage

My APS

Information for

About APS