Fingerprint Raman spectroscopy for two-dimensional MoS2 xSe2(1- x)alloys

Nikita Pimenov; Alexey Kartsev; Ekaterina Lebedeva; Elena Mishina

doi:10.1088/1361-648X/ad2e26

Fingerprint Raman spectroscopy for two-dimensional MoS_{2 x}Se_{2(1- x)}alloys

J Phys Condens Matter. 2024 Mar 14;36(23). doi: 10.1088/1361-648X/ad2e26.

Authors

Nikita Pimenov¹, Alexey Kartsev^{1

2

3}, Ekaterina Lebedeva¹, Elena Mishina¹

Affiliations

¹ MIREA-Russian Technological University, 78 Vernadsky Avenue, Moscow 119454, Russia.
² Computing Center of the Far Eastern Branch of the Russian Academy of Sciences, Khabarovsk 680000, Russia.
³ Peoples' Friendship University of Russia (RUDN University), 6 Miklukho-Maklaya St, Moscow 117198, Russia.

PMID: 38417174
DOI: 10.1088/1361-648X/ad2e26

Abstract

Two-dimensional transition metal dichalcogenides (TMDs) and alloys based on them, is a promising platform for creating opto- and nanoelectronic devices. For layered alloys, there is a strong need to theoretically determine the frequencies of vibrational modes and dependences of their energies on the stoichiometric composition. By comparing experimentally measured Raman modes with theoretical predictions, it becomes possible to determine the stoichiometric composition of the manufactured alloys. In this work, we investigated the vibrational properties of monolayer MoS_2xSe_2(1-x)alloys utilizing density functional theory method and confirmed them experimentally by Raman spectroscopy. The dependence of A₁' and E¹_2g'dactylographic' modes on the stoichiometric composition of alloys has been calculated. When in pure MoSe₂structure Se atoms are substituted by S atoms, the in-plane E¹_2g(S-Mo), E¹_2g(Se-Mo) and out-plane A₁' (S-Mo) modes shifted linearly inxto higher frequencies, while the out-plane A₁' (Se-Mo) mode did the same in nonlinear way. We also identified the E¹_2g(Se-Mo-S) mode, which specific for the MoS_2xSe_2(1-x)alloys and does not appear in pure two-component TMDs.

Keywords: Raman spectroscopy; density functional perturbation theory; semiconductors; two-dimensional alloys; two-dimensional transition metal dichalcogenides.