Unveiling the p-type character and optical properties of Ti-, Zr-, and Hf-Doped 1H-MoS2 monolayer for applications in nano-sized optoelectronic devices

Being a 2D material, the 1H-MoS 2 monolayer has emerged as a potential candidate for nano-sized devices requiring a tunable electronic structure. In this context, the incorporation of transition metal elements such as Ti, Zr and Hf as substitutional dopants at the Mo-site of a 2D 1H-MoS 2 monolayer appears to be a promising strategy for controlling its physical properties. To evaluate the impact of Ti, Zr and Hf atoms as substitutional dopants in a 1H-MoS 2 monolayer, we employed ab-initio density functional theory calculations at the meta-GGA level of theory to compute the atomic structure, thermodynamic stability and optoelectronic properties of these systems. We used the dispersion corrected r 2 SCAN+rVV10 meta-GGA functional, which shows good performance in predicting atomic structure and energetic properties. On the other hand, the electronic and optical properties of transition-mental doped 1H-MoS 2 monolayer have been examined using the lmBJ meta-GGA which is found to provide a relatively better description of the electronic properties when compared with r 2 SCAN+rVV10. Our results indicate that substitutional doping with Ti, Zr and Hf at a Mo-site is favourable and gives rise to a p -type semiconducting nature by introducing split off acceptor levels, which are mainly composed of Ti- 3d , Zr- 4d and Hf- 5d states located above the main valance band throughout the Brillouin zone of the 2D 1H-MoS 2 monolayer. Thus, introducing Ti, Zr and Hf dopants in 1H-MoS 2 monolayer facilitates the possibility of modulating the electronic and optical properties of this 2D material, which could prove beneficial for designing nano-sized optoelectronic devices.