Laser-Induced Chemical Patterning of Graphene-Black Phosphorus Hybrids

Black phosphorus (BP) and graphene are representatives of the class of two-dimensional (2D) materials, each material with its own outstanding and versatile properties. Creating hybrid systems between those materials allows us to combine the best of both worlds, and by tailored chemical modification, these heterostructure assemblies can be engineered and fine-tuned toward desired applications. This study systematically investigates laser-induced covalent functionalization of BP nanosheets and graphene-BP (G-BP) van der Waals (vdW) heterostructures using dibenzoyl peroxide-based precursors. Although pristine BP exhibits extreme sensitivity to laser irradiation, the formation of the G-BP heterostructure successfully enabled detailed Raman spectroscopy investigations and the successful spatially-resolved covalent functionalization of the graphene layer under mild laser conditions. Moreover, the G-BP hybrids revealed thickness-dependent intensity modulation of the graphene Raman bands due to interference effects, which was successfully modelled and exploited for the heterostructure characterization. The reversibility of the functional group attachment was investigated via temperature-dependent (T-dependent) Raman studies.