The crucial role of Many-body van der Waal interaction in Understanding the Stability of Point Defects in monolayer MoS₂

 

Arunima Singh* and Saswata Bhattacharya

 

Department of Physics, Indian Institute of Technology Delhi, New Delhi 110016

 

*Arunima.Singh[at]physics.iitd.ac.in

 

The present study investigates the stability of native point defects in MoS₂ monolayer by first-principles based approach under the framework of density functional theory (DFT). Owing to its abundance and the property of band gap transition from indirect to direct on going from bulk to single-layer, MoS₂ monolayer establishes a huge potential in semiconductor and optoelectronic industry. The synthesis or extraction of an element observes the presence of native defects, which becomes significant in exfoliation of different layers. Therefore, we study the stability of defects and put forward the prominence of certain defects at finite temperature conditions. This is achieved by ab-initio atomistic thermodynamics along with the DFT input. We have considered three vacancies and five antisites in our system^[1-2]. Our approach also includes the factor of two-body and many-body van der Waal (vdW) interactions in the defect studies^[3]. The many-body vdW interactions have posed a significant change in the pattern of stable defects. Moreover, the ground state property validates that the HSE06 functional addresses the present system accurately. We report the stable defect states as observed by HSE06 functional under many-body vdW interactions as , , , , , and . Finally, we obtain that these defects have significant concentration in the finite temperature range of 50K-1000K.

 

References:

[1] C. Gonzalez et al, Nanotechnology 27, 105702 (2016).

[2] H. P. Komsa et al, Physical Review B 91, 125304 (2015).

[3] H. Rydberg et al, Physical Review Letters 91, 126402 (2003).