Van der Waals solid phase epitaxy to grow large-area manganese-doped MoSe ₂ few-layers on SiO ₂ /Si

Abstract

Large-area growth of continuous transition metal dichalcogenides (TMDCs) layers is a prerequisite to transfer their exceptional electronic and optical properties into practical devices. It still represents an open issue nowadays. Electric and magnetic doping of TMDC layers to develop basic devices such as p-n junctions or diluted magnetic semiconductors for spintronic applications are also an important field of investigation. Here, we have developed two different techniques to grow MoSe 2 mono-and multi-layers on SiO 2 /Si substrates over large areas. First, we co-deposited Mo and Se atoms on SiO 2 /Si by molecular beam epitaxy in the van der Waals regime to obtain continuous MoSe 2 monolayers over 1 cm 2 . To grow MoSe 2 multilayers, we then used the van der Waals solid phase epitaxy which consists in depositing an amorphous Se/Mo bilayer on top of a co-deposited MoSe 2 monolayer which serves as a van der Waals growth template. By annealing, we obtained continuous MoSe 2 multilayers over 1 cm 2 . Moreover, by inserting a thin layer of Mn in the stack, we could demonstrate the incorporation of up to 10 % of Mn in MoSe 2 bilayers. * Electronic address: matthieu.jamet@cea.fr 1 arXiv:1906.03014v1 [cond-mat.mtrl-sci]

The search for manganese incorporation in MoSe 2 monolayer epitaxially grown on graphene

“…The red-dashed ellipses point out the absence of Mo or Se oxide in the sample as expected from the preparation protocol. The Mo and Se binding energies are compatible with previous results on MoSe 2 monolayers [20]. The series of Mn spectra shows an increased Mn 2p intensity upon increasing nominal concentration, evidencing that the effective Mn incorporation within the MoSe 2 layer keeps on increasing when increasing the initial Mn content.…”

“…In Refs. [20] and [19], the authors do not provide magnetic measurements and there is no direct proof of efficient magnetic doping and ferromagnetism in Mn doped MoS 2 and MoSe 2 . In contrast, in Refs.…”

“…In MoSe 2 , Mn atoms are expected to carry a spin moment of 1.27µ B and introduce gap states close to the Fermi level and at the bottom of the conduction band. However very few experimental achievements have been reported so far [13,[18][19][20]. In Ref.…”

“…In Ref. [20], the authors developed another growth method on SiO 2 called solid phase epitaxy where Mn atoms are not in direct contact with the SiO 2 substrate. It allows the incorporation of Mn atoms into MoSe 2 without evidence of Mn clustering.…”

Coherent imaging and dynamics of excitons in MoSe2 monolayers epitaxially grown on hexagonal boron nitride

“…14 Also molecular beam epitaxy of TMDs has been highlighted. 15,16 The optical response of the as-grown monolayers was dominated by the inhomogeneous broadening of the studied exciton transitions (EX), typically in a range of several tens meV. Moreover, the MBE growth of the materials incorporating transition metals, such as Mo and W, is particularly challenging owing to their low surface mobility.…”