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O: Fachverband Oberflächenphysik
O 47: 2D Materials II: Growth, Structure and Substrate Interaction I
O 47.7: Talk
Wednesday, March 29, 2023, 12:00–12:15, GER 37
Chemical vapor deposition of high optical quality large area monolayer Janus transition metal dichalcogenides — •A. George1, Z. Gan1, I. Paradisanos2, A. Estrada-Real2, J. Picker1, E. Najafidehaghani1, F. Davies3, C. Neumann1, C. Robert2, K. Watanabe4, T. Taniguchi4, X. Marie2, J. Biskupek5, M. Mundszinger5, R. Leiter5, U. Kaiser5, A. Krasheninnikov3, B. Urbaszek2, and A. Turchanin1 — 1Friedrich Schiller University Jena, Jena, Germany — 2Université de Toulouse, Toulouse, France — 3Helmholtz-Centre Dresden Rossendorf, Dresden, Germany — 4National Institute for Materials Science, Tsukuba, Japan — 5University of Ulm, Ulm, Germany
Large scale chemical vapor deposition growth of Janus SeMoS monolayers is reported, with the asymmetric top (Se) and bottom (S) chalcogen atomic planes with respect to the central transition metal (Mo) atoms. The formation of these 2D semiconductor monolayers takes place upon the thermodynamically driven exchange of the bottom Se atoms of the initially grown MoSe2 single crystals on gold foils with S atoms. The growth process is characterized by complementary experimental techniques including Raman and X-ray photoelectron spectroscopy, transmission electron microscopy, and the growth mechanisms are rationalized by first-principles calculations. The remarkably high optical quality of the synthesized Janus monolayers is demonstrated by optical and magneto-optical measurements which reveal the strong exciton-phonon coupling and enable to obtain an exciton g-factor of -3.3. (Adv. Mater. 34, 2022, 2205226)