Structural and electronic properties of pristine and chalcogen vacant 2H Janus XSeTe(X=W, V) monolayers and their heterostructures for potential use as an anode for metal ion battery

ORAL

Abstract

Janus monolayers and their heterostructures are now being potentially employed in the field of energy storage1. In this work, by using the First principles calculation adopting the Density Functional Theory (DFT)2 approach we explored the structural and electronic properties of 2H phase Janus XSeTe(X=W, V) monolayers and WSeTe/VSeTe heterostructures with and without chalcogen vacancies. VSeTe is predicted as a magnetic semiconductor with a bandgap of 0.26 eV whereas WSeTe is a nonmagnetic semiconductor with a band gap of 1.34 eV. We have made three heterostructures(HS), they are heterostructure 1(HS1), heterostructure 2 (HS2,)and heterostructure 3 (HS3 ) where HS3 is made by 30o twist between them, and HS1 is constructed by putting W atom below V atom and HS2 is formed by placing chalcogen atom(Se, Te) of VSeTe monolayer above W atom of WSeTe monolayer without any rotation. HS1 is calculated as a magnetic semiconductor while the other two HS are magnetic metals. VSeTe monolayer shows an adsorption energy of 1.45 eV for Li and 1.01 eV for Na ion which are higher than the adsorption energies shown by WSeTe. However, in between the layers, the adsorption energies increased for the HS. We have also studied the effect of Se and Te atom vacancies on the monolayers and HS3. Se and Te vacancy enhanced the adsorption energy of Li and Na atom. The calculated open circuit voltage falls in the range of 0.1 to 0.5V for both the monolayers and HS. The diffusion barrier for the VSeTe monolayer is found to be lower than WSeTe both for Li and Na ions.

* Shubham Sahoo acknowledges the financial support from Indian Institute of Technology, Patna, through Institute Fellowship.

–

Publication: 1. Sharma, A., Khan, M.S., Khan, M.S., Husain, M.: Ab initio study of molybdenum sulfo-selenides alloy as a flexible anode for sodium-ion batteries. Applied Surface Science 536, 147973 (2021).
2. Pople, J. A.; Gill, P. M.; Johnson, B. G. Kohn—Sham density-functional theory within a finite basis set. Chemical Physics Letters 1992, 199, 557–560.
3. H. Mehdipour, P. Kratzer, Structural defects in a Janus MoSSe monolayer: A density functional theory study, Physical Review B 106 (23) (2022) 235414.

Presenters

  • Shubham Sahoo

    Indian Institute of Technology Patna

Authors

  • Shubham Sahoo

    Indian Institute of Technology Patna

  • Subhasmita Kar

    IIT Patna, India, Department of Physics, Indian Institute of Technology, Patna - 801106, India

  • Puja Kumari

    Indian Institute of Technology patna, Department of Physics, Indian Institute of Technology, Patna - 801106, India

  • Neelam Gupta

    Indian Institute of Technology Patna, Department of Physics, Indian Institute of Technology, Patna - 801106, India

  • Soumya Jyoti J Ray

    IIT Patna, Indian Institute of Technology Patna, Bihta, Bihar-801106, Indian Institute of Technology Patna, Indian Institute Of Technology Patna, Department of Physics, Indian Institute of Technology Patna, Bihta 801106, India, Department of Physics, Indian Institute of Technology Patna, Bihta 801106, Department of Physics, Indian Institute of Technology, Patna - 801106, India