Electronic and optical properties of quantum emitters in h-BN

The study of two-dimensional nanometric materials has generated discoveries of new properties, such as the quantum emission of a single photon at room temperature in structures of hexagonal boron nitride (h-BN) due to the existence of defects related to vacancies and impurities or replacements by carbon. We used Density Functional Theory to study the electronic and optical properties of the h-BN monolayer, comparing it with other structures in which different types of defects in the crystal lattice caused by vacancies and/or antisites and substitutional carbon impurities were inserted. Electronic and optical band gap values were lower than those of the reference monolayer. The band structures showed new energy states, the wavelength range in which radiation absorption is amplified, and well-defined peaks between 1.2 and 2.2 eV appeared. These peaks are related to the quantum emission of a photon. The refractive index ranged from 1.28 to 1.66, depending on the structure, and the reflectance was below 38%. Therefore, the existence of these defects is capable of modifying the response of the material, such as its interaction with light and the appearance of new energy levels in the band structures.