Metal

Vacancy defect

Time-dependent density functional theory

Catalysis

Chemical physics

Materials science

Density functional theory

Transition metal

Biochemistry

Semiconductor

Dissociation (chemistry)

Band gap

Hybrid functional

Physical chemistry

Physics

Nanotechnology

Organic chemistry

Work function

Condensed matter physics

Computational chemistry

Monolayer

Crystallography

Chemistry

Chalcogen

Optoelectronics

Computational and Theoretical Chemistry

Defects usually play an important role in modifying the properties of the materials, therefore in this investigation an attempt has been made to understand the effect of chalcogen vacancy defect in various monolayer transition metal dichalcogenides (TMDCs). En route to probe the effect of defect, the density functional theory (DFT) calculations have been carried out. The results obtained from DFT calculations reveal that: (i) the nature of both chalcogen and metal significantly influences the dissociation energy, (ii) the work function of defective TMDC alters only marginally for both single or double vacancies, (iii) chalcogen vacancy converts direct gap (KV → KC) semiconductors into indirect gap semiconductors (ΓV → KC), and (iv) electronic bands clearly indicate that the d-orbital of the transition metal plays a vital role in the formation of impurity band.

Density functional theory based HSE06 calculations to probe the effects of defect on electronic properties of monolayer TMDCs