Abstract

Introduction: A systematic theoretical investigation of exciton sizes, their nature and natural transition orbital analysis has been presented for a number of graphene nanoflakes of varying shapes, sizes and isomeric forms. Interestingly, a variation in exciton sizes has been correlated to the size of the structure. The electron delocalization upon absorption has been presented using the natural transition orbital analysis and it is found to be navigating towards the edges of the structure, as the size increases.

Conclusion: The excitons were found to be Frenkel in nature.

Keywords: Graphene, DFT/TDDFT, exciton, natural transition orbital, nanoribbans, TPPFT.

Graphical Abstract