Exploring the electronic band gap of Janus MoSeO and WSeO monolayers and their heterostructures
Por:
Vo Van On, Duy Khanh Nguyen, Guerrero-Sanchez, J., Hoat, D. M.
Publicada:
15 nov 2021
Ahead of Print:
1 oct 2021
Resumen:
Designing new two-dimensional (2D) materials based on the Janus
structure has attracted great attention due to their novel properties
induced by out-of-plane symmetry breaking. In this work, we have
systematically investigated the structural and electronic properties of
TMSeO (TM = Mo and W) monolayers, which can be obtained by oxygenation
of the TMSe2 counterpart. Phonon dispersion curves confirm good
dynamical stability. MoSeO and WSeO pristine monolayers are Gamma-K
indirect gap semiconductors with energy gaps of 0.815(1.324) and
1.323(1.894) eV as determined using the PBE(HSE06) functional,
respectively. Our calculations show that a single vacancy of each
constituent atoms leads to magnetism-free 2D materials, although it
induces a considerable energy-gap reduction. A small lattice constant
mismatch between the MoSeO and WSeO monolayers allows the formation of
heterostructures. Depending on the stacking, vertical heterostructures
(VHSs) exhibit different electronic features, including being a
semiconductor with a variable band gap, a semimetal, and metallic in
nature. Meanwhile, in lateral heterostructures (LHSs) the semiconductor
behavior remains, for which the band gap increases according to an
increase in the WSeO block composition. This work provides a deeper
insight into the TMSeO monolayers as well as their effective gap
engineering based on the formation of defects and heterostructures. The
obtained results may introduce new 2D materials, which have the
potential for applications in high-performance optoelectronic nano
devices.
Filiaciones:
Vo Van On:
Thu Dau Mot Univ, Inst Appl Technol, Grp Computat Phys & Simulat Adv Mat, Thu Dau Mot, Binh Duong Prov, Vietnam
Duy Khanh Nguyen:
Thu Dau Mot Univ, Inst Appl Technol, Grp Computat Phys & Simulat Adv Mat, Thu Dau Mot, Binh Duong Prov, Vietnam
Guerrero-Sanchez, J.:
Univ Nacl Autonoma Mexico, Ctr Nanociencias & Nanotecnol, Apartado Postal 14, Ensenada 22800, Baja California, Mexico
Hoat, D. M.:
Duy Tan Univ, Inst Theoret & Appl Res, Hanoi 100000, Vietnam
Duy Tan Univ, Fac Nat Sci, Da Nang 550000, Vietnam
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