2 research outputs found
Creating Law at the Securities and Exchange Commission: The Lawyer as Prosecutor
Transition
metal dichalcogenides (TMDCs), together with other two-dimensional
(2D) materials, have attracted great interest due to the unique optical
and electrical properties of atomically thin layers. In order to fulfill
their potential, developing large-area growth and understanding the
properties of TMDCs have become crucial. Here, we have used molecular
beam epitaxy (MBE) to grow atomically thin MoSe<sub>2</sub> on GaAs(111)ÂB.
No intermediate compounds were detected at the interface of as-grown
films. Careful optimization of the growth temperature can result in
the growth of highly aligned films with only two possible crystalline
orientations due to broken inversion symmetry. As-grown films can
be transferred onto insulating substrates, allowing their optical
and electrical properties to be probed. By using polymer electrolyte
gating, we have achieved ambipolar transport in MBE-grown MoSe<sub>2</sub>. The temperature-dependent transport characteristics can
be explained by the 2D variable-range hopping (2D-VRH) model, indicating
that the transport is strongly limited by the disorder in the film
Intervalley Scattering of Interlayer Excitons in a MoS<sub>2</sub>/MoSe<sub>2</sub>/MoS<sub>2</sub> Heterostructure in High Magnetic Field
Degenerate extrema
in the energy dispersion of charge carriers
in solids, also referred to as valleys, can be regarded as a binary
quantum degree of freedom, which can potentially be used to implement
valleytronic concepts in van der Waals heterostructures based on transition
metal dichalcogenides. Using magneto-photoluminescence spectroscopy,
we achieve a deeper insight into the valley polarization and depolarization
mechanisms of interlayer excitons formed across a MoS<sub>2</sub>/MoSe<sub>2</sub>/MoS<sub>2</sub> heterostructure. We account for the nontrivial
behavior of the valley polarization as a function of the magnetic
field by considering the interplay between exchange interaction and
phonon-mediated intervalley scattering in a system consisting of Zeeman-split
energy levels. Our results represent a crucial step toward the understanding
of the properties of interlayer excitons with strong implications
for the implementation of atomically thin valleytronic devices