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
ISSN: 11440546





NEW JOURNAL OF CHEMISTRY
Editorial
Royal Society of Chemistry, THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND, Reino Unido
Tipo de documento: Article
Volumen: 45 Número: 44
Páginas: 20776-20786
WOS Id: 000712542300001