Article,
Spin polarized vertical transport in stacked TMDCs hetero-junctions
SEMICONDUCTOR SCIENCE AND TECHNOLOGY, (2018)
DOI: 10.1088/1361-6641/aacae9
Abstract
Electronic and transport properties of stacked metal/semiconductor and
metal/metal heterojunctions of transition metal dichalcogenides (TMDCs)
are studied in this paper. MoS2, MoSe2, WS2, and WSe2 are considered for
the semiconducting material, while NbS2, NbSe2, CoS2, and CoSe2 are
considered for the metallic contact. Our density functional theory-based
calculations reveal a strongly spin-polarized conductance for the
studied systems. Furthermore, our results predict that the band gap of
the semiconducting TMDC shifts above the Fermi energy of the connected
system, leading to a diode-like semiconductor/metal contact. Moreover,
the quantum conductance calculations for these junctions, carried out
within the Landauer-Buttiker formalism for ballistic transport, shows
that even the metal/metal heterojunctions have a diode-like character
near the Fermi level. This interesting behaviour is discussed in terms
of the misalignment between electronic states on each of the materials
comprising the junction.
