Effect of Substitutional Doping and Cu Adsorption on MoS ₂ Nanowire: A Comparative DFT Study

Abstract In this study, we have investigated the effect of substitutional doped (Cu‐doped MoS 2 NW) and surface‐adsorbed Cu atom (Cu‐MoS 2 NW) on the electronic properties of MoS 2 nanowire (NW) using Density Functional Theory (DFT). Our adsorption study revealed that the adsorption of the Cu atom was a chemisorption. Electron Localization Function (ELF) analysis indicates that the Cu atom formed a covalent and ionic bond with MoS 2 NW upon adsorption and substitutional doping, respectively. These findings indicate that a charge transfer occurred between the Cu atom and MoS 2 NW during the interaction, confirmed by the Bader charge method. Further, the work function calculation indicates that Cu‐doped MoS 2 NW exhibits a large negative variation in the work function, indicating enhanced electron emission capability of the Cu‐doped MoS 2 NW systems. All of our systems are thermodynamically stable based on our cohesive energy calculations. Overall, the DFT results suggest that Cu‐doped MoS 2 NW systems exhibit superior electrical conductivity, enhanced charge transfer, and larger variation in the work function compared to pristine MoS 2 NW and Cu‐MoS 2 NW. These findings confirmed that substitutional doping is an effective way to modify the electronic properties of MoS 2 NW. Therefore, Cu‐doped MoS 2 NW systems hold potential for applications in field emission and nanoelectronics devices.