2020

Hiltunen, Vesa-Matti; Koskinen, Pekka Johannes; Mentel, Kamila K.; Manninen, Jyrki; Myllyperkiö, Pasi; Johansson, Andreas; Pettersson, Mika

Graphene is not intrinsically luminescent, due to a lack of bandgap, and methods for its creation are tricky for device fabrication. In this study, we create luminescent graphene patterns by a simple direct laser writing method. We analyze the graphene using Raman spectroscopy and find that the laser writing leads to generation of line defects after initial formation of point defects. This Raman data enables us to create a model that explains the luminescence by a formation of small domains due to confinement of graphene by line defects, which is conceptually similar to the mechanism of luminescence in graphene quantum dots.