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DOE OSTI · 2551845

Type-I and type-II interfaces in a MoSe 2 /WS 2 van der Waals heterostructure

Rafizadeh, Neema [University of Kansas, Lawrence, KS (United States); The University of Kansas] (ORCID:0009000178079041)·Agunbiade, Gbenga [University of Kansas, Lawrence, KS (United States)] (ORCID:0000000159244024)·Scott, Ryan J. [University of Kansas, Lawrence, KS (United States)] (ORCID:0009000787002429)·Vieux, Monique [University of Kansas, Lawrence, KS (United States)]·Zhao, Hui [University of Kansas, Lawrence, KS (United States)] (ORCID:0000000345523836)
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Abstract

We report experimental evidence that MoSe 2 and WS 2 allow the formation of type-I and type-II interfaces, according to the thickness of the former. Heterostructure samples are obtained by stacking a monolayer WS 2 flake on top of a MoSe 2 flake that contains regions of thickness from one to four layers. Photoluminescence spectroscopy and transient absorption measurements reveal a type-II interface in the regions of monolayer MoSe 2 in contact with monolayer WS 2 . In other regions of the heterostructure formed by multilayer MoSe 2 and monolayer WS 2 , features of type-I interface are observed, including the absence of charge transfer and dominance of intralayer excitons in MoSe 2 . Furthermore, the coexistence of type-I and type-II interfaces in a single heterostructure offers opportunities to design sophisticated two-dimensional materials with finely controlled photocarrier behaviors.

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2D materials36 MATERIALS SCIENCEExcitonsHeterostructuresPhotoluminescence spectroscopyTransition metal chalcogenidesUltrafast laser spectroscopy

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Rafizadeh, Neema [University of Kansas, Lawrence, KS (United States); The University of Kansas] (ORCID:0009000178079041), Agunbiade, Gbenga [University of Kansas, Lawrence, KS (United States)] (ORCID:0000000159244024), Scott, Ryan J. [University of Kansas, Lawrence, KS (United States)] (ORCID:0009000787002429), Vieux, Monique [University of Kansas, Lawrence, KS (United States)], Zhao, Hui [University of Kansas, Lawrence, KS (United States)] (ORCID:0000000345523836). 2025-01-27. Type-I and type-II interfaces in a MoSe 2 /WS 2 van der Waals heterostructure. https://doi.org/10.1063/5.0253709

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