A5006718353- Semiconductor Quantum Structures and Devices
- Surface and Thin Film Phenomena
- Semiconductor materials and devices
- Molecular Junctions and Nanostructures
- Electron and X-Ray Spectroscopy Techniques
- Porphyrin and Phthalocyanine Chemistry
- Organic Electronics and Photovoltaics
- Electronic and Structural Properties of Oxides
- Surface Chemistry and Catalysis
- Advanced Chemical Physics Studies
- Spectroscopy and Quantum Chemical Studies
- Advanced Semiconductor Detectors and Materials
- Analytical Chemistry and Sensors
- Semiconductor materials and interfaces
- Lipid Membrane Structure and Behavior
- Force Microscopy Techniques and Applications
- Optical Coatings and Gratings
- Advancements in Battery Materials
- Photochemistry and Electron Transfer Studies
- Graphene research and applications
- Electrochemical Analysis and Applications
- Chemical and Physical Properties of Materials
- Spectroscopy and Chemometric Analyses
- Photonic Crystals and Applications
- Nanowire Synthesis and Applications
University of Rome Tor Vergata
2016-2025
Politecnico di Milano
2018
National Interuniversity Consortium for the Physical Sciences of Matter
2006-2015
University of Salento
2011
Istituto Nazionale di Fisica Nucleare, Roma Tor Vergata
2005-2006
Istituto Nazionale per la Fisica della Materia
1996-2004
University of Parma
2002
Istituto Nazionale di Fisica Nucleare, Sezione di Roma I
1992
Institute of Structure of Matter
1986-1991
The pivotal importance of TiO 2 as a technological material involves most applications in an aqueous environment, but the single‐crystal /bulk‐water interfaces are almost completely unexplored, since up to date solid/liquid more difficult access than surfaces ultrahigh vacuum (UHV). Only few techniques (as scanning probe microscopy) offer opportunity explore these systems under realistic conditions. rutile (110) surface immersed high‐purity water is studied by situ tunneling microscopy....
On-surface polymerization realized at the solid–liquid interface represents a promising route to obtain stable and conductive organic layers with tunable properties. We present here spectroscopic evidence of π-conjugated polymer formation between an iodine-modified Au(111) aqueous solution. Schiff-base coupling has been used drive reaction by changing pH. Scanning tunneling microscopy (STM) investigations show that substrate acts as template driving 1D ordered nanostructures. All chemical...
We have studied the controlled adsorption of molecules volatile compounds on thin Langmuir−Blodgett films porphyrins deposited onto surface a quartz microbalance. The modification film optical anisotropy has been measured by reflectance spectroscopy (RAS), and simultaneously, amount adsorbed monitored. Optical spectra after single analytes are interpreted straightforwardly in terms anisotropies related to H-like J-like aggregation modes porphyrins. By an appropriate selection analytes, we...
Using cyclic voltammetry (CV), reflectance anisotropy spectroscopy (RAS), and in situ electrochemical scanning tunneling microscopy (EC-STM), we have studied the structure structural transitions at a Cu(110) electrode surface 10 mM HCl solution as function of applied potential. While potentials lower than −550 mV vs Ag/AgCl STM images reveal adsorbate-free, unreconstructed surface, increasing potential ≥ chloride adsorption, indicated by CV, leads first to formation grooves followed growth...
A long-standing puzzle regarding the $\mathrm{Si}(111)\ensuremath{-}2\ifmmode\times\else\texttimes\fi{}1$ surface has been solved. The energy gap previously determined by photoemission on heavily $n$-doped crystals was not compatible with a strongly bound exciton known from other considerations to exist. New low-temperature angle-resolved and scanning tunneling microscopy data, together theory, unambiguously reveal that isomers opposite bucklings different gaps coexist such surfaces. subtle...
Porphyrins represent molecular building blocks for the development of a large variety functional materials. The control subtle intramolecular and intermolecular processes in solid porphyrin aggregates is promising establishment organic nanotechnology, which requires knowledge properties nanometric down to single atoms. Within this framework, optical anisotropy thin ultrathin metal-free tetraphenylporphyrin (H2TPP) films deposited on graphite carries interesting information related their...
In the present work, we used two different electrochemical (EC) techniques, namely, cyclic voltammetry and normal pulsed voltammetry, applied to a highly oriented pyrolytic graphite (HOPG) electrode for anion intercalation in aqueous electrolytes (i.e., perchloric sulphuric acid). We performed comparative X-ray photoemission (XPS) Raman spectroscopy studies at various EC potentials. The chemical analysis obtained by XPS spectroscopy, latter situ real time during processes, indicates that...
Reflectance anisotropy spectroscopy (RAS) has been employed to study in situ the growth of thin α-sexithiophene films by organic molecular beam deposition onto an substrate. A large can be detected following line shape evolution RAS spectrum; addition, signal variation at a fixed wavelength is used monitor film growth. The intensity scales with deposited thickness, demonstrating very high sensitivity less than 1/50 monolayer. Evidence advantages real time and probe their properties therefore...
Spontaneous deposition of aggregates a tetraphenylporphyrin derivative, possessing cationic appended functionality, straightforwardly occurs from aqueous solutions. Combined spectroscopic studies and AFM morphological characterisation reveal that these layered films feature consistent degree order. Deposition the related manganese or cobalt derivatives analogously UV-visible spectral pattern dramatically changes upon exposure to vapours amines olefins. This aspect can be great importance for...
Optical transitions between surface states associated with dangling bonds in $\mathrm{Si}(111)2\ifmmode\times\else\texttimes\fi{}1$ have been measured by means of reflection anisotropy spectroscopy the near infrared. The results confirm those previously obtained other optical techniques (namely differential reflectivity and photothermal deflection spectroscopies). method does not require oxidation thus opens way to studying a number problems physics, including temperature dependence...
We present a determination of the complex dielectric function Si(111) 2 × 1, GaAs(110) and GaP(110) surfaces by using polarized Surface Differential Reflectivity technique. The effective number electrons per atom participating in optical transitions is calculated for energies up to 4.0 eV each surface.
The optical gap between dangling-bond states has been measured on a single-domain diamond C(111)-2×1 surface. experimental result is 1.47 eV. Such large surface (even larger if excitonic effects are considered) so far not obtained by state-of-the-art band calculations and its physical origin still elucidated. suggests strong electron-phonon interaction in this renormalization of the bare electronic transition energy provides clue to solve apparent disagreement theory experiment.
The strained {105} facet, fundamental in the heteroepitaxial growth of Ge/Si(100), is investigated through a combination scanning tunneling microscopy, reflectance anisotropy spectroscopy, and density functional theory simulations. Besides providing strong independent confirmation proposed structural model, optical measurements give insight into Si/Ge intermixing, reveal hidden signatures buried interface, access to complementary viewpoint epitaxial with respect standard top-layer probing....
We have studied the optical anisotropy of porphyrin layers with different thicknesses deposited onto gold substrates by Langmuir−Schaefer technique. In coincidence Soret band molecule, spectral line shape as determined reflectance spectroscopy exhibits a characteristic, large structure, which changes from "peaklike" to "derivative-like" at well-defined thickness (8−10 monolayers). interpret this result in framework electronic effects due structural layers, yielding solid-state originating...
Reflectance anisotropy spectroscopy (RAS) is demonstrated to be particularly suitable for studying the deposition of organic epitaxial layers in ultrahigh vacuum by molecular beam epitaxy, thanks its high sensitivity and applicability situ. In case α-quaterthiophene, both homoepitaxy heteroepitaxy have been monitored, demonstrating crystallinity films up tens monolayers relation substrate. cases, optical RAS data are compared results ex situ characterization same samples atomic force microscopy.