Molecular beam epitaxy growth of Transition Metal Dichalcogenide (Mo,Mn)Se2 on 2D, 3D and polycrystalline substrates

Abstract

Magnetic doping of 2D materials such as Transition Metal Dichalcogenides is promising for enhancement of magneto-optical properties, as it was previously observed for 3D diluted magnetic semiconductors. To maximize the effect of magnetic ions, they should be incorporated into the crystal lattice of 2D material rather than form separated precipitates. This work shows study on incorporating magnetic manganese ions into the MoSe2 monolayers using molecular beam epitaxy. We test growth on various substrates with very different properties: polycrystalline SiO2 on Si, exfoliated 2D hexagonal Boron Nitride flakes (placed on SiO2/Si), monocrystalline sapphire, and exfoliated graphite (on tantalum foil). Although atomic force microscopy images indicate presence of MnSe precipitates, but at the same time, various techniques reveal effects related to alloying MoSe2 with Mn: Raman scattering and photoluminescence measurements shows energy shift related to presence of Mn, scanning transmission microscopy shows Mn induced partial transformation of 1H to 1T’ phase. Above effects evidence partial incorporation of Mn into MoSe2 layer.