title: Photoactive hybrid material based on pyrene functionalized PbS nanocrystals decorating CVD monolayer graphene.
abstract: A simple and facile solution-based procedure is implemented for decorating a large area, monolayer graphene film, grown by chemical vapor deposition, with size-tunable light absorbing colloidal PbS nanocrystals (NCs). The hybrid is obtained by exposing a large area graphene film to a solution of 1-pyrene butyric acid surface coated PbS NCs, obtained by a capping exchange procedure onto presynthesized organic-capped NCs. The results demonstrate that at the interface, multiple and cooperative π-π stacking interactions promoted by the pyrene ligand coordinating the NC surface lead to a successful anchoring of the nano-objects on the graphene platform which concomitantly preserves its aromatic structure. Interligand interactions provide organization of the nano-objects in highly interconnected nanostructured multilayer coatings, where the NCs retain geometry and composition. The resulting hybrid exhibits a sheet resistance lower than that of bare graphene, which is explained in terms of electronic communication in the hybrid, due to the interconnection of the NC film and to a hole transfer from photoexcited PbS NCs to graphene, channelled at the interface by pyrene. Such a direct electron coupling makes the manufactured hybrid material an interesting component for optoelectronics, sensors and for optical communication and information technology.
authors: CNR-IPCF sez. Bari, c/o Dipartimento di Chimica, Universitàdi Bari , via Orabona 4-I 70126 Bari, Italy.
authors: Chiara
authors: C
authors: Ingrosso
authors: Giuseppe V
authors: GV
authors: Bianco
authors: Michela
authors: M
authors: Corricelli
authors: Roberto
authors: R
authors: Comparelli
authors: Davide
authors: D
authors: Altamura
authors: Angela
authors: A
authors: Agostiano
authors: Marinella
authors: M
authors: Striccoli
authors: Maria
authors: M
authors: Losurdo
authors: M Lucia
authors: ML
authors: Curri
authors: Giovanni
authors: G
authors: Bruno
keywords: CVD monolayer graphene; colloidal PbS NCs; photoactive hybrid material