Directionally Selective Sensitization of ZnO Nanorods by TiOPc: A Novel Approach to Functionalized Nanosystems

• Published in: Journal of physical chemistry. C 2012-04, Vol.116 (14), p.8223-8229
• Main Authors: Coppedè, N, Calestani, D, Villani, M, Nardi, M, Lazzarini, L, Zappettini, A, Iannotta, S
• Format: Article
• Language: English
• Subjects: Applied sciences; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Electronics; Exact sciences and technology; Materials science; Molecular electronics, nanoelectronics; Nanocrystalline materials; Nanoscale materials and structures: fabrication and characterization; Nanotubes; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of low-dimensional, mesoscopic, and nanoscale materials and structures; Physics; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices
• ISSN: 1932-7447; 1932-7455
• DOI: 10.1021/jp3005184

We demonstrate for the first time the ability to selectively sensitize a specific area of nanorods in a forest, by kinetically activated processes, induced by a supersonic beam source. The experiments have been carried out on forests of ZnO grown by vapor phase deposition on aluminum doped ZnO. The highly supersonic beam, produced by seeding TiOPc in He, achieves a molecular kinetic energy larger than 15 eV. By exposing the ZnO forest at different angles with respect to the beam direction, we sensitized the nanorods on different specific sites, leaving the other parts completely clean, as confirmed by SEM and HR-TEM studies. The effective sensitization is demonstrated by photoexcitation spectroscopies, where the PL spectra indicate efficient energy transfer from the TiOPc molecule to the ZnO nanorods. Since this kinetical functionalization approach does not need molecules with specific linkers, the present results pave the way to novel multifunctional sensitization processes that we envisage to be uniquely suitable for hybrid photovoltaics, sensing, and biomedical applications.