Enhanced h-BN Nanosheets Through Adsorption and Point Defects for Two-Dimensional Electronic Applications: A DFT Study

Hexagonal boron nitride (h-BN) is a leading two-dimensional (2D) material that features an atomic structure similar to graphene but is characterized by its wide band gap and exceptional insulating properties, positioning it as a promising option for nanoelectronics and dielectric applications. Nevertheless, its relatively large band gap of approximately 6 eV restricts its applicability in electronic devices that demand semiconducting characteristics. Consequently, this research aims to enhance the electronic properties of h-BN nanosheets by incorporating point defects and nickel (Ni) adsorption on the surface, employing Density Functional Theory (DFT) calculations under the GGA-PBE approximation, as implemented in the CASTEP code. Starting from pristine h-BN, we constructed defective structures containing boron and nitrogen vacancies, along with Ni adsorbed at various surface sites. The findings indicated that the introduction of point defects resulted in local structural deformations around the defect sites, leading to a complete loss of the band gap and a shift in electronic behavior from an insulating to a conducting state. On the other hand, the adsorption of Ni established a strong interaction between the Ni 3d and N 2p orbitals, resulting in a reduction of the band gap to 0.58 eV, which signifies a transition from insulating to semiconducting behavior. These results demonstrate that enhancing the electronic properties of h-BN nanosheets through the introduction of point defects and Ni adsorption is an effective approach, making them promising candidates for two-dimensional nanoelectronics and nanophotonic applications.