Structure and morphology of 2H-MoTe2 monolayer on GaAs(111)B grown by molecular-beam epitaxy
Akihiro Ohtake, Xu Yang, Jun Nara
Abstract
Abstract The structure and morphology of monolayer 2H-MoTe 2 on GaAs(111)B grown by molecular-beam epitaxy have been studied using scanning tunneling microscopy, electron diffraction, and X-ray photoelectron spectroscopy. The MoTe 2 film grown and annealed under the Te-rich condition is mainly composed of a pure 2H phase, while, under the Te-deficient conditions, the 2H-MoTe 2 phase begins to evolve into nanowire-like structures owing to the desorption of Te. The 2H-MoTe 2 (0001) film on GaAs(111)B exhibits two types of energetically favorable epitaxial orientations; one is a perfect alignment of [11 $$\overline{2}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mover> <mml:mrow> <mml:mn>2</mml:mn> </mml:mrow> <mml:mo>¯</mml:mo> </mml:mover> </mml:math> 0]MoTe 2 // [1 $$\overline{1}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mover> <mml:mrow> <mml:mn>1</mml:mn> </mml:mrow> <mml:mo>¯</mml:mo> </mml:mover> </mml:math> 0]GaAs, and the other shows a slight in-plane rotation of ± 0.77 ∘ , which reduces the effective lattice mismatch between MoTe 2 and GaAs.