Electronic Properties of Defective MoS2 Monolayers Subject to Mechanical Deformations: A First-Principles Approach

Monolayers (MLs) of group-6 transition-metal dichalcogenides (TMDs) are semiconducting 2D materials with direct bandgap, showing promising applications in various fields of science and technology, such as nanoelectronics and optoelectronics. These MLs can undergo strong elastic deformations, up to about 10%, without any bond breaking. Moreover, the electronic structure and transport properties, which define the performance of these TMD MLs in nanoelectronic devices, can be strongly affected by the presence of point defects, which are often present in the synthetic samples. Thus, it is important to understand both effects on the electronic properties of such MLs. Herein, the electronic structure and energetic properties of defective MoS2 MLs are investigated as subject to various strains, using density functional theory simulations. The results indicate that strain leads to strong modifications of the defect levels inside the bandgap and their orbital characteristics. Strain also splits the degenerate defect levels up to an amount of 450 meV, proposing novel applications.