title: Growth of MoS(2(1-x))Se(2x) (x = 0.41-1.00) Monolayer Alloys with Controlled Morphology by Physical Vapor Deposition.
abstract: Transition-metal dichalcogenide (TMD) monolayer alloys are a branch of two-dimensional (2D) materials which can have large-range band gap tuning as the composition changes. Synthesis of 2D TMD monolayer alloys with controlled composition as well as controlled domain size and edge structure is of great challenge. In the present work, we report growth of MoS2(1-x)Se2x monolayer alloys (x = 0.41-1.00) with controlled morphology and large domain size using physical vapor deposition (PVD). MoS2(1-x)Se2x monolayer alloys with different edge orientations (Mo-zigzag and S/Se-zigzag edge orientations) have been obtained by controlling the deposition temperature. Large domain size of MoS2(1-x)Se2x monolayer alloys (x = 0.41-1.00) up to 20 μm have been obtained by tuning the temperature gradient in the deposition zone. Together with previously obtained MoS2(1-x)Se2x monolayer alloys (x = 0-0.40), the band gap photoluminescence (PL) is continuously tuned from 1.86 eV (i.e., 665 nm, reached at x = 0.00) to 1.55 eV (i.e., 800 nm, reached at x = 1.00). Additionally, Raman peak splitting was observed in MoS2(1-x)Se2x monolayer alloys. This work provides a way to synthesize MoS2(1-x)Se2x monolayer alloys with different edge orientations, which could be benefit to controlled growth of other 2D materials.
authors.affiliation: †Center for Nanochemistry, Beijing Science and Engineering Center for Nanocarbons, Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, P. R. China.|‡CAS Key Laboratory of Standardization and Measurement for Nanotechnology, National Center for Nanoscience and Technology, Beijing 100190, P. R. China.|§School of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, P. R. China.
authors.forename: Qingliang
authors.initials: Q
authors.lastname: Feng
authors.affiliation: †Center for Nanochemistry, Beijing Science and Engineering Center for Nanocarbons, Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, P. R. China.
authors.forename: Nannan
authors.initials: N
authors.lastname: Mao
authors.affiliation: †Center for Nanochemistry, Beijing Science and Engineering Center for Nanocarbons, Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, P. R. China.
authors.forename: Juanxia
authors.initials: J
authors.lastname: Wu
authors.affiliation: ∥School of Materials Science and Engineering, Shaanxi Normal University, Xi'an 710119, P. R. China.
authors.forename: Hua
authors.initials: H
authors.lastname: Xu
authors.affiliation: §School of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, P. R. China.
authors.forename: Chunming
authors.initials: C
authors.lastname: Wang
authors.affiliation: †Center for Nanochemistry, Beijing Science and Engineering Center for Nanocarbons, Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, P. R. China.
authors.forename: Jin
authors.initials: J
authors.lastname: Zhang
authors.affiliation: ‡CAS Key Laboratory of Standardization and Measurement for Nanotechnology, National Center for Nanoscience and Technology, Beijing 100190, P. R. China.
authors.forename: Liming
authors.initials: L
authors.lastname: Xie
keywords: MoS2(1−x)Se2x; Raman spectrum; alloy; morphology; physical vapor deposition; tunable band gap