(Invited) Porphyrinoid-Carbon Nanostructure Ensembles and Fused Porphyrin-Graphene Nanoribbons

Phthalocyanines (Pcs) have emerged as excellent light harvesting antennas for incorporation into D-A systems, mainly in connection with carbon nanostructures, like endohedral metallofullerenes, SWCNT and graphene, as acceptor or donor moieties, in which the Pc has been attached, covalently or through supramolecular interactions. They are among the few molecules that reveal an intense red and NIR absorption and therefore, constitute also promising dyes in molecular photovoltaics. Pcs have a great chemical versatility, which allows to modify their electronic character and their physicochemical properties by organic synthesis, by introducing substituents in the periphery or modifying the structure of the macrocycle. Most recently they have reached good efficiency values participating as hole transporting materials in Carbon-based Perovskite sensitized solar cells (PSSCs). Pcs are be appropriately designed to adapt well to the electronic levels of the different types of perovskites. Through a rational design, structure-property relationships will be established that will gradually improve the performance of the devices. On the other hand, on-surface synthesis offers a versatile approach to fabricate novel carbon-based nanostructures that cannot be obtained via conventional solution chemistry. Within the family of such nanomaterials, graphene nanoribbons (GNRs) hold a privileged position due to their high potential for different applications. One of the key issues for their application in molecular electronics lies in the fine-tuning of their electronic properties through structural modifications, such as heteroatom doping or the incorporation of non-benzenoid rings. In this context, the covalent fusion of GNRs and porphyrins (Pors) represents a highly appealing strategy.