title: Simultaneous Hosting of Positive and Negative Trions and the Enhanced Direct Band Emission in MoSe2/MoS2 Heterostacked Multilayers.
abstract: Heterostacking of layered transition-metal dichalcogenide (LTMD) monolayers (1Ls) offers a convenient way of designing two-dimensional exciton systems. Here we demonstrate the simultaneous hosting of positive trions and negative trions in heterobilayers made by vertically stacking 1L MoSe2 and 1L MoS2. The charge transfer occurring between the 1Ls of MoSe2 and MoS2 converted the polarity of trions in 1L MoSe2 from negative to positive, resulting in the presence of positive trions in the 1L MoSe2 and negative trions in the 1L MoS2 of the same heterostacked bilayer. Significantly enhanced MoSe2 photoluminescence (PL) in the heterostacked bilayers compared to the PL of 1L MoSe2 alone suggests that, unlike other previously reported heterostacked bilayers, direct band transition of 1L MoSe2 in heterobilayer was enhanced after the vertical heterostacking. Moreover, by inserting hexagonal BN monolayers between 1L MoSe2 and 1L MoS2, we were able to adjust the charge transfer to maximize the MoSe2 PL of the heteromultilayers and have achieved a 9-fold increase of the PL emission. The enhanced optical properties of our heterostacked LTMDs suggest the exciting possibility of designing LTMD structures that exploit the superior optical properties of 1L LTMDs.
authors.affiliation: Center for Integrated Nanostructure Physics, Institute for Basic Science, Sungkyunkwan University , Suwon 440-746, Republic of Korea.
authors.forename: Min Su
authors.initials: MS
authors.lastname: Kim
authors.affiliation: Center for Integrated Nanostructure Physics, Institute for Basic Science, Sungkyunkwan University , Suwon 440-746, Republic of Korea.|Department of Energy Science, Sungkyunkwan University , Suwon 440-746, Republic of Korea.
authors.forename: Changwon
authors.initials: C
authors.lastname: Seo
authors.affiliation: Center for Integrated Nanostructure Physics, Institute for Basic Science, Sungkyunkwan University , Suwon 440-746, Republic of Korea.|Department of Energy Science, Sungkyunkwan University , Suwon 440-746, Republic of Korea.
authors.forename: Hyun
authors.initials: H
authors.lastname: Kim
authors.affiliation: Center for Integrated Nanostructure Physics, Institute for Basic Science, Sungkyunkwan University , Suwon 440-746, Republic of Korea.|Department of Energy Science, Sungkyunkwan University , Suwon 440-746, Republic of Korea.
authors.forename: Jubok
authors.initials: J
authors.lastname: Lee
authors.affiliation: Center for Integrated Nanostructure Physics, Institute for Basic Science, Sungkyunkwan University , Suwon 440-746, Republic of Korea.|Department of Energy Science, Sungkyunkwan University , Suwon 440-746, Republic of Korea.
authors.forename: Dinh Hoa
authors.initials: DH
authors.lastname: Luong
authors.affiliation: Center for Integrated Nanostructure Physics, Institute for Basic Science, Sungkyunkwan University , Suwon 440-746, Republic of Korea.
authors.forename: Ji-Hoon
authors.initials: JH
authors.lastname: Park
authors.affiliation: Center for Integrated Nanostructure Physics, Institute for Basic Science, Sungkyunkwan University , Suwon 440-746, Republic of Korea.
authors.forename: Gang Hee
authors.initials: GH
authors.lastname: Han
authors.affiliation: Center for Integrated Nanostructure Physics, Institute for Basic Science, Sungkyunkwan University , Suwon 440-746, Republic of Korea.|Department of Energy Science, Sungkyunkwan University , Suwon 440-746, Republic of Korea.
authors.forename: Jeongyong
authors.initials: J
authors.lastname: Kim
keywords: heterobilayer; interlayer charge transfer; molybdenum diselenide; molybdenum disulfide; negative trions; positive trions