Modulation du spectre infrarouge du graphène
Graphene is a promising nanomaterials thanks to its excellent mechanical, optical and electrical properties. However, its most innovative applications require that it be altered, but the understanding altered graphene is still limited.  Some applications are considered in infrared optics. However, our current understanding of graphene does not explain the appearance of the infrared peaks that are observed in bilayers and grafted monolayers. The behaviour of grafted graphene is especially baffling, since the addition of grafts makes it more transparent, not less!  A model proposed by Bruno Rousseau, a postdoctoral student of Professor Michel Côté at Université de Montréal, suggests an explanation for this phenomenon: although the phonons of graphene cannot couple directly with light, they could couple indirectly through collisions with the electrons, which can couple with photons. This indirect coupling may produce constructive and destructive interference, depending on the conditions, so this mechanism can produce absorbance peaks as much as transparency peaks.  In this master’s thesis, we have undertaken to experimentally verify the validity of this model, and we conclude that it seems to adequately predict the behaviour of the infrared activity of graphene bilayers and grafted monolayers. We also studied the methods by which we synthesized these different types of graphene to optimize them. Finally, we determined techniques based on Raman spectroscopy to characterize the intensity of the alteration induced by these methods.
Twisted bilayer graphene Grafted graphene Infrared spectroscopy Raman spectroscopy Drude model Fano resonance