Ab initio study of the nitrogen doped Si43C44H76 nanoparticle: Time-dependent density functional theory

•Nitrogen-doped SiC nanocrystal can form thermodynamically stable structure.•Surface carbon substitutional defects are interesting for binding the nitrogen impurity.•The nitrogen impurity can significantly change the optical absorption.

Electronic and optical properties of the various nitrogen-doped Si43C44H76 nanoparticles investigated with time-dependent density functional theory. The binding energies of the nitrogen atom as an impurity in the silicon, carbon substitutional defects and also for the interstitial defects were analyzed. The changes in the energy gap between highest occupied molecular orbital and lowest unoccupied molecular orbital were discussed for various doped systems. Finally the optical excitation and exciton binding energy of the pure and stable nitrogen-doped Si43C44H76 nanoparticles derived from time-dependent density functional calculation.