Incorporating different dopants, such as nitrogen or boron, into graphene can significantly alter its electronic structure and properties. Density functional theory DFT calculations are a powerful computational tool used to study these changes at the atomic and electronic level. By understanding the effects of dopants on graphene, researchers can tailor its properties for various applications, such as sensors, transistors, and energy storage devices.1. Nitrogen doping: Nitrogen has one more electron than carbon, so when it replaces a carbon atom in the graphene lattice, it introduces an extra electron into the system. This results in the formation of localized states near the Fermi level, which can increase the electrical conductivity of graphene. DFT calculations show that nitrogen doping can transform graphene from a zero-gap semiconductor to a n-type semiconductor. The presence of nitrogen also introduces local strain and distortion in the graphene lattice, which can affect its mechanical properties.2. Boron doping: Boron has one less electron than carbon, so when it replaces a carbon atom in the graphene lattice, it creates a hole a missing electron in the system. This results in the formation of localized states near the Fermi level, which can increase the electrical conductivity of graphene. DFT calculations show that boron doping can transform graphene from a zero-gap semiconductor to a p-type semiconductor. Similar to nitrogen doping, the presence of boron also introduces local strain and distortion in the graphene lattice, which can affect its mechanical properties.In summary, doping graphene with nitrogen or boron can significantly change its electronic structure and properties. DFT calculations can help researchers understand these changes and design graphene materials with tailored properties for specific applications. Nitrogen doping generally results in n-type semiconducting behavior, while boron doping leads to p-type semiconducting behavior. Both dopants introduce local strain and distortion in the graphene lattice, which can affect its mechanical properties.