Graphene and other 2D materials, such as transition metal dichalcogenides TMDCs and hexagonal boron nitride h-BN , exhibit unique electronic and optical properties due to their atomic thickness and strong in-plane covalent bonding. When doped with nitrogen or boron atoms, these properties can be significantly altered, leading to new functionalities and potential applications.1. Electronic properties:a Graphene: In its pristine form, graphene is a zero-bandgap semiconductor with a linear energy dispersion near the Dirac points. When doped with nitrogen or boron atoms, the electronic properties change significantly:- Nitrogen doping: Nitrogen atoms have one more electron than carbon atoms, so when they replace carbon atoms in the graphene lattice, they introduce extra electrons, making the graphene n-type. This increases the electron concentration and enhances the electrical conductivity. Additionally, nitrogen doping can open a bandgap in graphene, making it a more suitable material for electronic devices.- Boron doping: Boron atoms have one less electron than carbon atoms, so when they replace carbon atoms in the graphene lattice, they introduce holes, making the graphene p-type. This increases the hole concentration and enhances the electrical conductivity. Like nitrogen doping, boron doping can also open a bandgap in graphene.b Other 2D materials: Doping other 2D materials, such as TMDCs and h-BN, with nitrogen or boron atoms can also modify their electronic properties, such as bandgap, carrier concentration, and conductivity.2. Optical properties:a Graphene: Pristine graphene has a unique optical property, as it absorbs a constant 2.3% of incident light over a broad wavelength range. Doping with nitrogen or boron atoms can alter the optical properties by introducing localized states in the band structure, which can lead to changes in the absorption spectrum and the appearance of new optical features.b Other 2D materials: The optical properties of other 2D materials, such as TMDCs and h-BN, can also be modified by doping with nitrogen or boron atoms. This can result in changes in the absorption and emission spectra, as well as the appearance of new excitonic features and photoluminescence peaks.In summary, doping graphene and other 2D materials with nitrogen or boron atoms can significantly modify their electronic and optical properties, leading to new functionalities and potential applications in optoelectronics, sensors, and energy storage devices.