title: Probing Evolution of Twist-Angle-Dependent Interlayer Excitons in MoSe2/WSe2van der Waals Heterostructures.
abstract: Interlayer excitons were observed at the heterojunctions in van der Waals heterostructures (vdW HSs). However, it is not known how the excitonic phenomena are affected by the stacking order. Here, we report twist-angle-dependent interlayer excitons in MoSe2/WSe2vdW HSs based on photoluminescence (PL) and vdW-corrected density functional theory calculations. The PL intensity of the interlayer excitons depends primarily on the twist angle: It is enhanced at coherently stacked angles of 0° and 60° (owing to strong interlayer coupling) but disappears at incoherent intermediate angles. The calculations confirm twist-angle-dependent interlayer coupling: The states at the edges of the valence band exhibit a long tail that stretches over the other layer for coherently stacked angles; however, the states are largely confined in the respective layers for intermediate angles. This interlayer hybridization of the band edge states also correlates with the interlayer separation between MoSe2and WSe2layers. Furthermore, the interlayer coupling becomes insignificant, irrespective of twist angles, by the incorporation of a hexagonal boron nitride monolayer between MoSe2and WSe2.
authors.forename: Pramoda K
authors.initials: PK
authors.lastname: Nayak
authors.affiliation: Center for Multidimensional Carbon Materials (CMCM), Institute of Basic Science (IBS) , Ulsan 44919, Republic of Korea.
authors.forename: Yevhen
authors.initials: Y
authors.lastname: Horbatenko
authors.forename: Seongjoon
authors.initials: S
authors.lastname: Ahn
authors.forename: Gwangwoo
authors.initials: G
authors.lastname: Kim
authors.affiliation: Department of Physics, Sogang University , Seoul 04107, Republic of Korea.
authors.forename: Jae-Ung
authors.initials: JU
authors.lastname: Lee
authors.forename: Kyung Yeol
authors.initials: KY
authors.lastname: Ma
authors.forename: A-Rang
authors.initials: AR
authors.lastname: Jang
authors.affiliation: Department of Chemistry, Chonnam National University , Gwangju 61186, Republic of Korea.
authors.forename: Hyunseob
authors.initials: H
authors.lastname: Lim
authors.affiliation: Department of Chemistry, Pohang University of Science and Technology (POSTECH) , Pohang, Gyeongbuk 790-784, Republic of Korea.
authors.forename: Dogyeong
authors.initials: D
authors.lastname: Kim
authors.affiliation: Department of Chemistry, Pohang University of Science and Technology (POSTECH) , Pohang, Gyeongbuk 790-784, Republic of Korea.
authors.forename: Sunmin
authors.initials: S
authors.lastname: Ryu
authors.affiliation: Department of Physics, Sogang University , Seoul 04107, Republic of Korea.
authors.forename: Hyeonsik
authors.identifier: 0000-0002-2347-4044
authors.initials: H
authors.lastname: Cheong
authors.affiliation: Center for Multidimensional Carbon Materials (CMCM), Institute of Basic Science (IBS) , Ulsan 44919, Republic of Korea.
authors.forename: Noejung
authors.initials: N
authors.lastname: Park
authors.affiliation: Center for Multidimensional Carbon Materials (CMCM), Institute of Basic Science (IBS) , Ulsan 44919, Republic of Korea.
authors.forename: Hyeon Suk
authors.identifier: 0000-0003-0495-7443
authors.initials: HS
authors.lastname: Shin
keywords: density functional theory; interlayer exciton; photoluminescence spectroscopy; transition-metal dichalcogenide; twist angle; van der Waals heterostructure